Super Mario 64 again :P
Killer Instinct on the SNES, followed closely by Top Gear.
I think the first game I actually beat by myself was breath of fire on snes
First game I ever beat was in kindergarten or first grade. Ham Ham Heartbreak for gameboy. Still have it and beaten it multiple times... it is my childhood. Lol
The first game I ever beat was Super Mario 64. I think I was 6-7 when it happened. Lol after I beat it I started crying because I did not want the game to end. XD
Sonic 2 for me, Sanic along with other genesis stuff like streets of rage 2, altered beast, mortal kombat, etc were literally the first video games I've played in general.
I can't really remember clearly, though I guess Mario Kart 64, if you can count that?
If you're talking about a game with a specific main campaign, I really don't know...