IMPORTANT! If this is your first time watching, then it's strongly recommended you watch this series in Release Order for best enjoyment, this is because the author planned the story out of order, and watching chronologically spoils some parts, while not knowing what happened before creates a more interesting story.
If you already watched the whole series, then it's ok to 'rewatch' in chronological order so you can understand it better, or just get a different experience:
This is a light shounen (no blood & gore) and a good iteration of the Demons vs Humans theme, in this case in the form of exorcists. Perhaps, one of the best parts of the story is the implied premise that ponders: Are we born good or evil, or is this the result of the environment and how we are raised? Can tolerance and kindness transform someone who should be the embodiment of evil into an asset for society?
I recommend you watch without fillers, as the plot of the anime contains fillers at the end diverging significantly from the manga. And then, that filler ending of the first season is ignored in the second season anyway, with the anime story timeline once again following the narrative of the manga. So in this regard, you can stop watching at 19 minutes of Episode 17, before the fillers start, or you can keep watching up to filler Episode 18, to complete that story, which is ok. Then move to the Kyoto Saga.
The filler story of season 1 is not terrible (although it contradicts itself at some points) but is perhaps best left to the end, as an alternative ending, in order to not spoil parts of the better story in the Kyoto Saga.
The dub is great.
This guide includes all different instances & spin-offs of the series:
Not exactly a Watching Guide per se, but a collection of animes with Great Art!
The 1999 version has more detail of the earlier events and it's better at giving you an insight into the character's observation skills and way of thinking, it focuses more in the puzzles and critical thinking, it also has a darker tone than the 2011 version which focuses more on the action, fun, and it's more kid-friendly. The 2011 version quickly recaps the first arcs, missing crucial insights that make the story shine, so I recommend you start with the 1999 version and subsequent OVAs, then jump to the 2011 version at Episode 75 (or Episode 54 if you skip the OVAs or you are watching the Dub). You won't be missing any major events if you decide just to watch the 2011 version and if you are not into dark animes then you may prefer this version (not that there is more gore or violence but rather the way the story is told).
(Same as above)
Note that the first story and probably the best of them all is actually the last 3 episodes of Ayakashi - Japanese Classic Horror (Bake Neko Story), which is the best part of that anime to such extent, that spawn this standalone series. So you should probably start there.
This show is also featured on this list: Animes with Incredible Art
This anime suffers from an identity crisis, for starters, the mafia here is portrayed more like 'Justice League of Superheroes' rather than an actual mafia. Then at the beginning of the series starts up with the ridiculous slice of life episodes that quickly get extremely monotonous and boring, but somehow necessary to watch in order to introduce all characters, which in this anime are a lot. Finally, after 70+ episodes, it changes into a glorious shonen anime, full of action that won't stop until the end. This last part is usually what receives the best ratings. Ironically, even filler arcs at the end, turn out better than the cannon life episodes!
I strongly recommend you to skip the 'Life' episodes for a better experience:
This is what I recommend from the whole series and I recommend you watch in Release Order:
Although The Lost Canvas is a prequel, it's better to watch it after the original series as you are expected to know everything about the world.
Spinoffs: None of the recent spinoffs are worth watching, neither the 2019 remake.
Movies: None of the movies are worth watching, some have good animation, but the stories are always rushed and none are canon as far as I know.
If you want to see the whole franchise you can follow this list:
I recommend watching the subs. The English Dub is ok, but I think they censor some scenes. The Latin Dub is way superior with the voice actors so that one is also a good choice if you understand Spanish, but I'm not sure if it's censored.
Also known as 'Kara no Kyōkai' this movie series has excellent animation & an intriguing supernatural story with something meaningful to say. Make sure you watch to the end of each movie.
The story is in anachronical order, but release order is strongly recommended, especially for the first time watching the series. Otherwise, you lose some of the intrigues. You can rewatch the series in chronological order at a later time.