Oh! Edo Rocket

They both have this crazy yet enjoyable sense of humor that just makes you laugh. 

Both series take place in bizarre alternate universe late-Edo-period Japan after the arrival of aliens. Both series have random, crazy humor and very entertaining characters. Oh! Edo Rocket has more actual plot and drama though. Also both feature the talents of Kugimiya Rie (Kagura/Shunpei). 

Both are not-so-historical anime set in feudal Japan, that employ elements of comedy, action, and western music to give themselves a unique flavor. Samurai Champloo tends to be more serious and has a hip-hop soundtrack, while Edo Rocket is more lighthearted with a jazz soundtrack. Both also follow a relatively episodic plot in which the characters attempt to get closer to a set goal. 

Storywise these two anime couldn't be more different. But I find the humor and the mix between the humor and drama to be very similar. 

Same crazy mix of parody-comedy action with nevertheless a strong and complicated story. "Gurren" originates from super robot mecha animes, "Edo Rocket" from harem-type with this special girl that just falls on protagonist's head=) They both exploit some common themes but do it in a bit unexpected fashion. 

Both are very funny anime. If Oh Edo Rocket was a multiverse it would be like Abenobashi. For the greatest effect start watching Azumanga Daioh, then The melancholy of Haruhi Suzumiya, then Lucky Star, then Kannagi(the last three are strongly connected), then go deeper in the universe of otaku with Genshiken(think of it as Lucky star after high school, at university), chill of with Sketchbook full color (similar to Azumanga Daioh), combine all of them into Pani Poni Dash, then go nuts with Abenobashi Mahou Shoutengai, and top it off with Oh Edo Rocket, and enter the long run with Gintama. Other funny anime that I didn't find where to put them in the list above are :Ichigo Mashimaro, School Rumble, Ouran High School Host Club and some others. However to understand the jokes from Genshiken, Pani Poni Dash and Gintama you need to know about other anime's.  read more 

Both are probably the funniest animes ever. I have never seen more 4-th wall breaking anywhere else. For the greatest effect start watching Azumanga Daioh, then The melancholy of Haruhi Suzumiya, then Lucky Star, then Kannagi(the last three are strongly connected), then go deeper in the universe of otaku with Genshiken(think of it as Lucky star after high school, at university), chill of with Sketchbook full color (similar to Azumanga Daioh), combine all of them into Pani Poni Dash, then go nuts with Abenobashi Mahou Shoutengai, and top it off with Oh Edo Rocket, and enter the long run with Gintama. Other funny anime that I didn't find where to put them in the list above are :Ichigo Mashimaro, School Rumble, Ouran High School Host Club and some others. However to understand the jokes from Genshiken, Pani Poni Dash and Gintama you need to know about other anime's. read more