Ike! Ina-chuu Takkyuu-bu

- The same toilet humour - lots of perverted crazy characters ( e.g. sadistic female, pure hearthed, yet crazy giant) - the main hero is the most normal person in group 

Watch the first episode of each and you will see alot of slapstick comedy and numerous toilet humor. If you are really into that kind of thing this is 100% reccomendation by me.  

MC in both series get to the sports club. But crazy characters do anything but a sport. In both series humor is perverted and dirty.  

Same style of humour, perverted, dirty, arranged mainly with teenager boys betwen them.  

Probably the two funniest anime I've seen. Even if you don't care about school life and music themed anime (I don't) both are definitely worth watching if you like inappropriate humor. Suitable for adults. 

Same ginger haired badass chick who doesn't want to be there but likes a guy in the club, the club has a couple characters that have similar roles (pretty boy, generic leader guy). Both clubs are full of perverts and all they do is talk about perverted junk, the only differences to me is: one is ping pong, the other is a fan club; Genshiken doesn't actually show the private parts and Ping Pong Club does. 

Kodocha and ping pong club leaving you pretty similar feeling after watching episodes. That feelings of old school awesomeness and derpy jokes. and those opening and endings quite similar.  

Both shows are based on the lives of adolescent high school boys and their antics. Ike! Ina-chuu ... (aka Ping Pong club) is centered on the crazy happenings at a high school ping pong club. Common themes in both DKNN and Ina-Chuu include weird interactions with members of the opposite sex, cross-dressing, interference in romance and other perverted plots you can blame on puberty. Ping pong club though takes it to the extreme and features nudity. Expect a regular dose of butts and boobs. While DKNN has much better humour, Ping pong club has is own lol moments in the form of outrageous actions by a perverted trio and lots of gags. Table tennis itself has little role to play unlike the title suggests. Unlike DKNN, this is not a show you can watch with your family, but provides great laughs. If you enjoy adolescent comedy this show is definitely recommended. read more 

Random, dirty humor. Ike! Ina-chuu is way more perverted, though 

both hilarious, ping pong club is more lewd and toiler humor though 

Recommended only for guys as a comedy. Both are about the school days of some perverted teenagers and their practical jokes and adventures, both have toilet humor, both will make you laugh till you drop, although I have to say Ping Pong Club is not only the source of inspiration for Green Green, but also for GTO in some ways. Ping Pong Club however doesn't deal with the nudity in a sexy way but in a funny way, unlike Green Green. You might also find Ping Pong Club a lot more exagerated. 

Same crazy guys in a school setting with over-the-top humor. Ping Pong Club is more perverted though.  

Weirdness and ecchi-humor at it's best! 

Both are comedies with same art styles, sex innuendos and random humor.  

Gyagu Manga Biyori is more for short unconnected stories, Ping Pong Club has some storyline and a bit more sense, but humor is similar in both of them: wacky, vulgar and sometimes very topical.