Gintama, Oh! Edo Rocket Recommendations
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 very funny anime and both are placed in a similar world.
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