I would definitely have to agree with Super Mario World as one of the greatest games of all time, just from the memories I have of playing it back when I was a child, and because it's so fun to hack.
And I would have to say another game would be Roller Coaster Tycoon 2. It provided me with countless hours of entertainment, and is clearly one the best (If not the best) of the tycoon game franchise. I never really got truly into #1 and #3 of the series though, but I just love how there is still a fanbase for it.
Oh! And I completely forgot Majora's Mask, best Zelda game ever.