Games you should try playing some day (in no particular order).

1.) X-com: UFO defense
2.) Civilization (1,2,3 or 4)
3.) Wing Commander
4.) Baldur''s Gate 1 and 2
5.) Star Wars: Tie-Fighter
6.) Doom
7.) Aliens Versus Predator (demo as marine)
8.) Freedom Force
9.) Space Quest I-IV
10.) Unreal Tournament
11.) SSI Ad&d Dragonlance (Silver Box series)
12.) Police Quest 1-3
13.) City of Heroes/City of Villains
14.) Star Control 2
15.) Diablo 2