Episode numbers in this list are according to the original numbers, and not the numbers given by funimation (see wikipedia Detective Conan Episodes for details).
1) Black Organization Arcs (Main Plot: Reduced to around 250 episodes)
If you are only interested in the main plot that covers the Black Organization's conspiracy, the following episodes are relevant. Major character introductions and developments are included. Sticking to the episodes in bold letters will help get you through the main plot very quickly, but you will come across side characters and character developments you do not know if you skip episodes not marked in bold. The characters in Detective Conan are intricately related to one another, which is what makes this series special. Therefore, I advise you not to skip any of these.
-> Intro arc reduced to 17 episodes 🤭
-> Sherry arc reduced to 6 episodes
-> Vermouth arc reduced to 60 episodes
-> Kir arc reduced to 34 episodes
-> Bourbon arc reduced to 82 episodes
-> Rum arc reduced to 58 episodes, ongoing
2) Best of Best Episodic Case Mysteries
These are episodic side stories that have nothing to do with the Black-org main plot, but are masterpiece episodes that involve hardcore detective work in often macabre and sinister cases of mystery. Highly recommended that you watch at some point.
-> total of 28 selected episodic episodes
3) Shinichi-Ran Canon Arcs
These are canon episodes that focus specifically on the romance between the two main protagonists. Highly recommended that you watch at some point.
-> 33 episodes
4) Kaitou Kid Episodes
Kaitou kid (the thief) is one of the most important side characters in the Detective Conan franchise, who made his first appearance in the series as a mysterious thief/magician and a rival of Detective Conan. Since then, numerous episodes have been dedicated to narrating Kaitou Kid's battle against several other side characters in the show. If you’ve finished watching episodes related to the main plot and are interested in knowing more about Kaito Kid, watch these episodes below.
[Fun fact: Kaito Kid has his own manga franchise, and this franchise existed long before Detective Conan.]
-> 30 episodes
5) Metropolitan Police Department Series
These are side stories that focus on cases involving members from the Metropolitan Police Department. The majority of these is plain romance rather than serious mystery. Recommended if you’ve finished watching episodes relating to the main plot and are interested in the side characters belonging to the police.
-> 42 episodes
6) Police Academy Arc
Side stories that focus on the character Amuro Tohru and his past.
7) Hattori Heiji Related Case Files
Heiji is one of the very few people who know Conan's true identity. Recommended if you’ve finished watching episodes relating to the main plot and are interested in the side character Hattori Heiji.
-> 90 episodes
8) Kyougoku Makoto and Sonoko Related Episodes
Side stories that focus on the romance between Karateka Kyougoku Makoto and Suzuki Sonoko.
9) Kisaki Eri's Court Case Files
Side Stories that focus on the professional life of lawyer Kisaki Eri and her relationship with Mouri Kogorou. Recommended if you’ve finished watching episodes relating to the main plot and are interested in the side characters Kisaki Eri and Mouri Kogorou.
-> 25 episodes
Watch - Watch any time after having watched up until episodes 770-771* The Tense Tea Party, and 772-773 Shinichi Kudo Aquarium Case.
This is a TV special (written by the original mangaka) and an in depth retelling (*not a recap) of the first episode of the Detective Conan series. This TV special retells the episode from the viewpoint of characters that have appeared after episode one and up until episode 771. Episode 772-773 is not important to the main plot, but serves as a prequel to the TV special.
Skip - TV special not relevant to the main plot. The mystery was meh.
Skip - A recap episode of the black-org arc aired on TV that is meant to be seen before episode 491 The Clash of Red and Black.
Skip - A recap of episodes 309-311 Contact With The Black Organisation, aired on TV before episode 491 Clash of Red and Black.
Skip - Recap of episodes 491-504* Clash of Red and Black all the way to 779-783* The Scarlet series, in theatres for 3 weeks only, meant to be watched before movie 24 The Scarlet Bullet.
Skip - Recap of the Jet-Black Mystery Train arc, to be watched before Movie 26 Kurogane no Submarine.
All movies from the Detective Conan franchise are made so that they don't add to or deviate from the main plot told in the TV series. Therefore, the movies are completely optional. If you are going to watch the movies, though, I strongly suggest watching each movie after having watched up until certain episodes of the TV series, since the movies (aired every year) generally tend to feature characters in parallel to new characters introduced in the TV series.
Skip - This is the very first movie from the franchise. The mystery in this one is good but underwhelming. The story highlights the romance between Shinichi and Ran.
This was aired straight after episode 54, but watchable anytime after episode 6 Valentine Murder Case (=Introduction of Suzuki Sonoko) of the TV series.
Optional (Recommended) - I recommend this one personally because it depicts the process of a detective's work in an interesting way; as Ran struggles to understand the cause behind Kogorou's past 'misdeed', she discovers that she can not arrive at the truth based on facts alone.
It is revealed in this movie that Conan, as a child, was trained by his father on how to use a gun and fly a helicopter.
This was aired straight after episode 97, but watchable anytime after episode 32 Coffee Shop Murder Case of the TV series (=after the introduction of Kisaki Eri).
Optional (Recommended) - I recommend watching this movie for its production value. The general atmosphere in this show is fabulously mysterious, as the story involves treasure-hunting in a historical castle, Russian spies and the mysterious Kaitou Kid. This is also the first movie that features Kaitou Kid and Hattori Heiji.
Aired straight after episode 140, but watchable anytime after episode 130-131 The Indiscriminate Threatening Stadium Case (=after the introduction of Haibara Ai).
Optional (Recommended) - Recommended because this one is considered to have one of the most emotional and traumatic storylines in the movie franchise. Recommended after watching the first of the Metropolitan Police Detective series (episodes 146-147) because a lot of the characters from this episode appear in this movie.
Aired straight after episode 186, but watchable anytime after episode 146-147 Metropolitan Police Detective Love Story.
Skip - This is the first movie that is black-organization related. It doesn't add anything to the main plot of the TV series, but the black org appearance does make the story dramatic. It also touches on the character development of Haibara Ai that is seen in episodes 130-131 of the TV series.
It is revealed in this movie that Conan, as a child, was taught by his dad on how to drive a car.
Aired straight after episode 230, but watchable anytime after episode 130-131 The Indiscriminate Threatening Stadium Case.
Optional (Recommended) - Recommended as movie 6 is deemed among fans as a masterpiece. It really is a masterpiece, story-wise, setting-wise, and character-wise.
Aired straight after episode 274, but watchable anytime after episode 130-131 The Indiscriminate Threatening Stadium Case (=after the introduction of Haibara).
Skip - For fans of Hattori Heiji. Basic knowledge of the romantic relationship between Kazuha and Hattori, Ran and Shinichi is required.
Aired straight after episode 315, but watchable anytime after episode 220-224 And Then There Were No Mermaids (major character development between Kazuha and Hattori) .
Skip - For fans of Kaitou Kid. Knowledge of the character development of Kaitou Kid is required.
A revelation is made that Conan knows how to fly an airplane.
Aired straight after episode 356, and watchable anytime after episode 356 Kaito Kid's Miraculous Midair Walk (major Kaitou Kid episode).
Skip - For fans of Mouri Kogorou since there is a rare highlight of Kogorou's judo and deduction. Basic knowledge of the romantic relationship between Ran and Shinichi is required.
Aired straight after episode 393.
Skip - Detectives galore. Includes detectives who appeared in episode 219. Knowledge of the character development of Kaitou Kid is also required.
Aired straight after episode 434, but watchable anytime after episode 219 The Gathering of the Detectives! Shinichi vs Kaito Kid.
Skip - For anyone who is interested in the friendship between Ran and Sonoko. Also for anyone who wants to see Ran do karate underwater. Basic knowledge of the romantic relationship between Ran and Shinichi may be required, but is not a must.
Aired straight after episode 469.
Skip - Watchable just for the classical soprano music. Basic knowledge of the romantic relationship between Ran and Shinichi is required.
Aired straight after episode 501.
Optional (Recommended) - Recommended because it's black org related. Again, the story does not add on to the main plot told in the TV series, but it's thrilling nonetheless.
Aired straight after episode 530, but watchable anytime after episode 425 Black Impact! The Moment the Black Org Reaches Out! (=introduction of regular black org members) .
Skip - Somewhat entertaining. Another movie that features Kaitou Kid. There's alot of action in this one, and some emerging bromance between Conan and Kaitou Kid. Basic knowledge of the relationship development between Conan and Kid is necessary. The VA for Mouri Kogorou has changed from Kamiya Akira to Koyama Rikiya.
Aired straight after episode 570, but watchable after episode 356 Kaito Kid's Miraculous Midair Walk (introduction of Jirokichi).
Skip - Contains loads of skateboarding action. Tearjerking. Basic knowledge of the relationship between Shinichi and Ran is necessary.
Aired straight after episode 610.
Skip - Largely insignificant plot that revolves around football.
Aired straight after episode 651.
Skip - Largely insignificant plot that revolves around Japan's national navy defence.
Aired straight after episode 693.
Skip - A rare case in which a major main-plot related revelation is made in a movie. The mystery itself was underwhelming though, so I’d recommend watching just for the plot revelation. Basic knowledge of Sera Masumi and Okiya Subaru is required.
Aired straight after episode 734. It means a lot when you watch this straight after episode 734 Jodie's Memories and the Cherry Blossom Viewing.
Skip - Another Kaitou Kid related movie. Basic knowledge of Kaito Kid and his accomplices is necessary.
Aired straight after episode 773, watchable after episode 356 Kaito Kid's Miraculous Midair Walk (=major Kaito Kid episode).
Optional (Recommended) - Another black org related and thrilling movie that contains lots of action and a climax that touches on the conflict between Akai and Amuro. Basic knowledge of Kir, Akai and Amuro is necessary.
Aired straight after episode 813, watchable after episode 810-812 The Darkness of the Prefectural Police.
Skip - For those who are interested in the romance between Heiji and Kazuha. Basic knowledge of the relationship between the two is required. The plot is unremarkable.
Aired after episode 855, but best watched after episode 916-917 Kendou Tournament of Love and Mystery and before episode 927-928 The Crimson School Trip.
Skip - For fans of Amuro Tohru, as the story focuses on the professional duties of Amuro. Basic knowledge of Amuro is necessary.
Aired straight after episode 898, but watchable after episode 779-783 (The Scarlet series).
Skip - For those who are interested in the battle between Kyogoku Makoto and Kaitou Kid, and the romantic relationship between Kyogoku and Sonoko. The mystery and plot are unremarkable.
Aired straight after episode 936, but watchable after episode 746-747 Kaito Kid vs Makoto Kyogoku.
Skip - This was delayed a year due to Covid. It features the Akai family and is to be watched by fans of the Akai family. The plot was unremarkable.
Episode 1002 was aired to promote this movie. Watchable after episodes 971-974* The Target is the Metropolitan Police Traffic Department, in which the connection between the Akai family members is officially confirmed.
Optional (Recommended) - The plot is directly linked with episode 304 Trembling Metropolitan Police Headquarters and 12 Million Hostages. The movie also features Amuro Tohru and characters from the TV special 'Keisatsu Gakkou-hen' so watching the TV special will therefore be a prerequisite for enjoying this movie. Episode 1039 was aired to promote this movie.
The mystery was very good, and the plot made use of Episode 304 and Keisatsu Gakkou-hen extremely well. This is top level fan service for fans of the franchise. The music is also very different from the previous films (Yuugo Kanno has replaced Katsuo Ohno as composer), but it really suits the movie.
Recommended after watching the following episodes:
Skip - Black-org related, focusing on Haibara. Aired after episode 1080. This is for fans of Haibara.
Action-packed, not much focus on the mystery, but an interesting integration of recent technology into the story. The plot is gripping enough to keep you on the edge of your seat. You'd need to be up to date with the main series to fully enjoy since there are quite a lot of internal references to the main plotline of the TV series (at least up until the Mystery Train Arc).
Kir's Arc -
Haibara's arc -
Skip - A crossover of the Detective Conan and Lupin 3rd franchise. Comedy. Lots of fun for audiences who know both franchises.
Skip - 2nd crossover of the Detective Conan and Lupin 3rd franchise.
Optional - This was a 12 episode series that was spontaneously aired in place of Detective Conan episodes between 2010-2012. Fans like to say that Kaito Kid 'hijacked' Conan's broadcasting frame.
The series is based on the original manga Magic Kaito (penned by the same mangaka as Detective Conan, and existed before Detective Conan), and focuses on the life of Kaitou Kid. The most interesting thing about this series is that the major Kaitou Kid episodes (i.e., first 30 minutes of episode 219 The Gathering of the Detectives) that were aired in the Detective Conan franchise are retold from Kaitou Kid's perspective.
I would recommend watching the Kaito Kid episodes I listed above (even at least up until episode 219), if you truly want to enjoy the parallel story-telling.
The opening sequence of the series is a parallel of the opening animation sequence used in the detective conan series (Openings 32 and 34 of the Detective Conan series).
Skip - This is a remake of the Magic Kaito series, albeit by a different studio. They changed the character design, animation style and VAs, massively. Conan makes cameo appearances in this version as well.
It’s made so that it is watchable without prior knowledge of the Detective Conan series.
Skip - A short episode spin-off that focuses on the private life of Amuro Tohru. The life of Amuro Tohru when he’s not at work involves his pet dog Halo and cooking. Made for fans of Amuro Tohru.
The show is relaxing to watch, but the production value is like that of the filler episodes of the TV series, and it has zero significance to the main story.
Skip - A spin-off that depicts the life of 'the black-silhouetted criminal', a character trope in the detective conan series. Comedy.
The show was amusing to watch. It was a harmless 5-minutes episode per week comedy that jokes about the high death rates in Beika city, Ran's overpowered karate skills and other canon jokes.
TBA - focuses on Kaito Kid and Heiji