Dragon Quest IX- World's Biggest Selling game.

Jan 2005
18,468
Waco, TX
http://kotaku.com/5397646/dragon-quest-ix-is-the-biggest+selling-game-in-the-world

The handheld RPG sold 3.93 million units, well clear of Wii Sports Resort, the game in second place (with 3 million). In third was Madden 10, on 2.6 million, while Pokemon Heartgold & Soulsilver sold 2.1 million and Halo 3: ODST 1.8 million.

Sales from between July and September is what is shown here. Amazing what the NDS and one RPG can do.