Inukami!, Sora no Otoshimono Recommendations
Others have recommended animes like Chobits or DearS. While these animes are similar in story, they don't have the same feel as Sora no Otoshimono. The humor of Sora no Otoshimono has the exact same tone as Inukami. Extremely ridiculous, over the top, ecchi humor that is presented in a unique way. This is interspersed within more serious arcs that provide the occasional relief from the outrageous comedy.
Basically, if you laughed your ass off watching Inukami, you will find yourself doing the same for Sora no Otoshimono.
The same good humor and ecchi, some of a a few ecchi animes i've enjoyed.
Quite obviously both feature "pervert main male leads but dependable in times of need", and feature harem and one original girl who fell in love with him. Both also have unique censors for the main guy's manhood, who often goes around naked.
Inukami: More of youkai and supernatural
Sora no Otoshimono: Angeroids
Both feature tons of slice-of-life, and school life (if i rmb correctly) too
Instead of the usual bland and generic male protagonists we get super horny ones with a harem of super powered girls.