My favorite game was Mario and the Legend of the Seven Stars. I've wanted to play that again ever since I was a little kid, but could never find it again! I also loved Super Mario Kart, and have never seen another 'kart' game that could compare. Also, Super Mario Bros. and Super Mario World...apparently I was a Mario kid.
When I was -really- young, I played a few computer games. One about these two monkey-kid things, one boy and one girl, who were in this treehouse. It's probably called 'The Treehouse' or something. And then there was this other game where you played a scuba diver who swam around shining his flashlight on stuff to find hidden fish or something. When you solved a puzzle, it would complete more of a rainbow. No idea what that one was called.