Sales-wise, it's Mario ahead of Pokemon, no matter how you look at it. The interesting question (and the one you're really asking) is really the third place. Or, if you count the Wii series, the fourth place.
If you go by overall sales in the 7th generation, it's actually Brain Training, with 35.24 million. Zelda is well below that, 23.39 million including Link's crossbow training. Nintendogs, with just the one game, finishes above Zelda.
In terms of lifetime sales, Zelda still holds the third/fourth place, with 75.38 million. Donkey Kong isn't far behind, with 59.98 million. Kirby is pretty far off, at just 33 million, behind Brain Training (35.24) and Tetris (35.84) and just barely ahead of Duck Hunt and Nintendogs. Smash Bros is below all of those, with just 24 million.
Sales-wise, nothing Nintendo (or well, really anyone at all) has comes close to matching Mario. On the Wii alone, Mario has sold more than Zelda and Kirby have across all their machines. Mario Kart - by itself - is, with 95 million sold, comfortably larger than Zelda, and the 4 New Super Mario Bros. games outdo all of the Donkey Kong games combined. Mario Party (34.76 million) beats all of Kirby. 3D Mario platformers (46 million) outdo Metroid (17 million), Star Fox (11 million), Fire Emblem (8 million), F-zero (6 million) and Pikmin (4 million) combined.
Oh, and for the record, Mario passed 500 million sold lifetime just this week. I'm surprised you haven't made a thread yet, Spurge.
