...That is, games that are (or at least were) actually special; different, and not just the average thing. Bad or good doesn't matter.
I think System Shock counts as one. I haven't played anything like that before.
Preferably something with awesome interface. Yes, I love them interfaces. Especially when they blend into the game and doesn't feel like something on the side - like in Bioforge (where you use your characters hand to navigate the menus), Metroid Prime (HUD on the visor), Fallout 3 (pip-boy), most space slight sims, etc.
Oh, and it has to be for DOS.
