Crusader No Remorse / No Regret is excellent, but a bit iffy to get running, the CD version did pretty well for me once I was able to convince dos box to recognize my drive after the installation.
The story of Tie Fighter is supposed to be amazing, but the visuals are a bit hard to swallow after so much time. (a remake due if anyone is asking me)
One Must Fall 2097, Duke Nukem 3D, Jazz Jackrabbit, the fabulous Epic Pinball series, and Raptor: Call of the Shadows are all good choices.
and if you only pick one game, try out Solar Empire, its a fabulous game. It even has a great sequel.
My guess is that availability of the games is going to be the hardest thing, finding old dos software is tough.