IIIIITHE1IIIII on 22 December 2012
That would be the DS, at the moment. Greatest software library for a handheld ever, in my opinion. Spent countless hours playing the mini games in Super Mario 64, playing Mario Kart DS and lots of third party titles. Prior to that I pretty much only used my handhelds as Pokémon machines (with few exceptions such as the Sonic Advance games and Toy Story Racing).
With Super Smash Bros. coming to the 3DS along with Luigi's Mansion: Dark Moon and lots of other upcoming first party titles, I would expect the 3DS to get past it eventually though. We shall see.
