Hentai Games (R=18)

No eroge novels (aka 'erotic visual novels') nor dating sims in this list: there are so many of them that we would need another page just for them.

ZONE games aren't really games, but sweet Jesus does 4chan love them and each one is well-made. They are in a separate list below.

The Types are:
 * DOS - You'll probably need an emulator like dosbox.
 * Windows - herp
 * Flash - derp
 * NES, SNES - derpity-derp
 * Playstation2 - the only hentai games that aren't Ameritrash were visual novels; move along
 * Atari 2600 - ... wait, what?

ZONE games
All ZONE games are in english, are flash and they're NOT free (you have demos though), you can get them at his/her website.