I know its been mentioned but Turican II is probably one of the best games ever made.
Deluxe Galaga and Delux Packman by the late Edgar M. Vigda are also great games
+1. Also second the votes for the SSI "Gold Box" games (Pool of Radiance, etc.) if you like that kind of game.
Also tossing in a vote for Battle Squadron. You can find clips of all these games on YouTube to see if they perk your interest.