I don't really think that much of Mario, especially recently... but Super Mario Bros. 3? Some of the best memories of my life, definitely of my gaming life. Me, my dad and my sister gathered around that little screen, doubting our ability to get to the next Koopa Kid, let alone beat them... having to restart every time the power went out... but eventually, together, making it all the way and finishing the game. You know what the best part was? No c**k-slap ending, or bad gameplay, like SMB2.
Then again, this was his baby, and at least he's critical of his own past work in a constructive way.