There are so many amazing Mario games out there, that picking one is nearly impossible for me lol. But if I had to pick, it would probably be Super Mario 64 with my runner up being Super Mario Galaxy.
Currently Playing: Mario Kart 7, Mario Kart 8, Luigi's Mansion: Dark Moon, The Legend of Zelda: Majora's Mask, Super Smash Bros for Wii U
Predictions:
Super Mario Galaxy will pass Super Mario 64 in total sales CORRECT!