If you're looking for anime similar to Gintama, you might like these titles. All recommendations are made by Anime-Planet users like you!
Hozuki is the aide to the Great King Enma. Calm and super-sadistic, Hozuki tries to resolve the various problems in Hell, including a rampaging Momotaro and his companions. However, he also likes spending his free time on his hobbies, such as fawning over cute animals and raising ‘Goldfish Flowers.’
Gintama is far more crazy, but both it and Hoozuki no Reitetsu share a similar style of comedy. They're random, fun, and overall just really silly. Gintama can get a little serious and even sad at times while Hoozuki shows no signs of that, but if you're looking for some good comedy and nonsense, you may want to look here.
Space Dandy is a space hunter, someone who is paid to search for new, undiscovered alien species. It's an industry where the prize goes to the person who finds aliens the fastest. Dandy searches unknown planets for strange beings with his companions, QT the worn-out robot and Meow from Betelgeuse. Meanwhile, they're being chased by minions of the Gogol Empire, for reasons that are still a mystery.
The story is set in the Bakumatsu era, at the end of the shoguns' rule over Japan in the middle of the 19th century. The Tokugawa shogunate uses the brainwashing "Heaven's Songs" by the top idols in Shinsengumi to subjugate the country and its people. In this Japan, writing or singing any songs besides the "Heaven's Songs" is a capital offense. Ryōma Sakamoto and the other rockers rise up and change the world with rock 'n' roll for freedom and justice.