I dropped it the first episode after I saw those acid tits. I watch anime for their plot and story. If I want to see sexy stuff, I would go watch hentai.
Dear God Yosuga no Sora made me feel dirty as hell after three episodes!I went back(because I'm not a pussy) and finished the rest and can officially say that my mind got blowed. That was just hentai they had sex in the final episodes at least three times! EACH!!!
Tenjou Tenge (manga) if you like the Air Gear art style its the same guy except with full nudity, Seikon no Qwaser (read the manga, I enjoy it more)
Someone mentioned Futari Ecchi, its based off a manga by the same name thats over 100 chapters of the couples sexual adventures. I guess you could consider it hentai though. Theres another similiar one by the same guy about an average joe who becomes engaged with an idol.
And of course To-Love-Ru Darkness, always pushing the border.
I was going to say "inb4 to love ru" but now that i think about it, miraculously falling and stripping every girl you come across cant hold a candle to twin sisters fapping on your bed.
Aki-Sora, Futai Ecchi, Love Lucky, Nozoki Ana, Yomeiro Choice, Koibana Onsen, Nyotai-ka, Virgin na Kankei, Boku no Futatsu no Tsubasa, Itoshi no Kana, Yosuga no Sora, Koi wo Suru no ga Shigoto Desu, and Haru Yo Koi.