first, some pong-like game on someone's zx spectrum in early 80ties. it was brief and short but very first experience. later, karateka, tetris, games like that on my and others C64.

the first game i was hooked to was Elite on same C64. it was just wow. 3d, freedom, trading, pirating, leveling up. i played only Elite for long time, played it on Amiga and my first 386 later on. still stands as my first serious gaming memory.