I have been playing games for over 25 years now and i think that easily makes me a veteran in the world of gaming. The first game I that got me hooked into gaming was cannon fodder, it was the first game I completed and since then i haven't stopped.
What game got you hooked ?
Commodore 64: Fire Ant and Sub Sunk.
I was always getting annoyed in Sub Sunk when I tried to do something and it would tell me "you can't do that" when I asked it why, it just said "because you can't". The developers must have anticipated what people would ask and had the answers ready, even when I started to swear at the game it would come back with "tut,tut, such language".
Those were the days...
If we're going back to the Atari then it has to be Doom that got me hooked.
Probably the earliest I recall was an arcade game - Space Invaders when it came out in 1978.
Some early games I remember;
Colossal Cave Adventure (Commodore Pet, small green CRT screen, text only)
3D Monster Maze (ZX-81)
Night Flight (ZX-81)
Gulpman (Spectrum)
3D Ant Attack (Spectrum)
JetPac (Spectrum)
Manic Miner (Spectrum)
Jet Set Willy (Spectrum)
Racing Destruction Set (Spectrum)
Hungry Horace / Horace Goes Skiing (Spectrum)
Revs (Commodore 64)
Elite (Commodore 64)
Various Commodore Amiga games
Doom (PC)
... and the rest is history.
I remember games like Racing Destruction Set had 4 tapes, each double sided, it took an AGE to load, if it loaded at all. The early days were frustrating.