Arakawa Under the Bridge, Danshi Koukousei no Nichijou Recommendations
You will constantly laugh your head off watching these.
I know both don't have the same story and one is a shounen and the other a seinen but both have in common the comedy style, they have weird characters in their way, both are randomness.
I'm sure if you like one, you may like the other too.
Another one that was very similar in terms of comedy
Highly compressed hilarious randomness. Must I say more?
Warning: Danshi Koukousei no Nichijou starts out a little slower and takes a few episodes to get epic.
Both are absolutely nonsensical and absolutely hilarious in similar and different kinds of ways
The viewers will notice that the environment(setting) of both anime is similar!
We should mention that both anime have the same kind of humour and wittiness, and I can't distinguish which is more hilarious.
Nevertheless, Arakawa Under the Bridge has more of a story to present!!!
Both are over the top, absurdist comedies. Danshiko is the funniest anime I have ever watched, one that manages to make me and my friends laugh even during rewatches. It doesn't have much plot if any, unlike Arkawa. Arakawa's humor kind of wore thin for me, whereas Danshiko kept me laughing for its entirety. Danshiko's strong suit was how it was so funny while still being grounded in reality (i've seen some the scenarios in Danshiko being played out in real life). Both are anime that you probably wouldn't regret watching (I prefer Danshiko), but if you just want to really laugh, watch Danshiko, if
Slap Stick Comedy and utter randomness
If you laugh so hard in danshi koukousei, I assure you really laugh 10x in arakawa under the bridge + cute romance. Both produced by "sunrise studio"