The first GTA game I had ever played. Before this, my cousin had introduced me to 007: GoldenEye for N64. That was the most violent game i'd ever played. Then I was at his place a couple years later, and he was playing GTA 3. I wasn't shocked at how much i liked it, but i was very certain my parents wouldn't....which of course made me all the more desperate to play more.
It turned out I was wrong: shortly afterward, my dad decided i was getting old enough to make these decisions on my own, and actually told me when he saw the game at a second hand store. I now own every GTA game made for PS1,2,3.
I didn't try the 1st one very long before i gave up trying to revert back to a more 2-dimensional world, but i'm running out of games to try. I'll prolly go at it with a vengeance before too long.