Super Mario 64, although it took me a while to get to 120 (I was bad at games)
If my memory is correct it has to be pokemon red
Halo 2 was my first, and that was through pure luck... Back then I was so incompetent with games that I would be wandering one stage endlessly either due to not knowing the objective, or constantly dying. Now, if it isn't a souls-like, I beat it with relative ease (except with Resident Evil 4, beat it on PC, can't beat it on XBOne for some reason...).
Naruto ultimate ninja for the PlayStation 2
The Legend of Zelda, Oracle of Ages or Pokemon Silver. Don't remember which I beat first.
Either Zelda Ocarina of Time or golden eye 007.
102 Dalmatians : Puppies To The Rescue
frigging nostalgia trip right now xdd
Sonic The Hedgehog I assume, I had the sega 6-Pak for my Genesis as my first 6 games, I played all of them not really sure which one I beat first.
Pokemon Fire Red
I did play the original red version but at that time me and my siblings all shared the gameboy and the game and we constantly would delete each others save data and restart, so none of us ever beat it