Hmm... Doom, Keen, Return to Zork, the 7th Guest, the QBasic Centepede and Gorilla games, Duke, the Learning Company's SuperSolver games (especially OutNumbered!), the (Even More) Incredible Machine, Amazon Trail, Word Muncher & Number Muncher, SMB+Duck Hunt, SMB3, Megaman 2. I remember some earlier ones but no way would I remember the names.