Are "Serious Sam: The First Encounter" and "Neverwinter Nights" considered as older games?
Anyway, my I enjoyed much playing:
Duke Nukem 3D,
Wolfenstein 3D,
Mortal Kombat Series,
Street Fighter (every one, which had the Boxer as a playable character),
Pokemon Series,
Tank (Not sure about the name, anyway, stuff was for Pegasus, so you've got to know the exact game now. ;))
Crime Fighters 2 aka Vendetta,
Puzzle Bobble (Bust-A-Move),
Raptor (Not sure about the name, it was a top-down shooter).
Darn, I played many good games and I still play some.