If you want something like Otoboku (male oriented) try "I! My! Me! Strawberry eggs", I liked it, though people tend to say it's shit because of the drama.
I second Princess Princess, although it's more female oriented, but it's funny on it's own, so I still managed to enjoy it.
H2O, Minami-ke and Moysashimon have good traps, but they're not the focus of the show. Ouran's main character is a REVERSE trap.
If you want something with porn, Boku no Pico and Okane ga nai are as close as it gets. Boku no Pico is pure fapping material (not that that is a bad thing), Okane ga nai has some GAR thrown into the mix, but suffers from QUALITY and too much rape drama. Also, both suffer from censored sex scenes.