Beating Angel! Dokuro-chan (Pretty funny and violent, but is very ecchi too.)
Onegai Twins.
Onegai Teacher.
Kodomo no Jikan (If you like loli, this anime is so close to hentai it's not even funny.)
Rizelmine
If you can find the Hand Maid May OVA, I suggest you find it. It's about a porn director using the robots to make porn. (Doesn't show the sex, just shows them moaning.) The name of it is Hand Maid Mai. I could only find one episode of it, sorry.