Definitely the DS, it has the best software support. I own the other two, but the PSP never had the games (except for a few), and the IPod touch just doesn't feel like a real gaming console. The IPod has some really cool games, and some that are on par with older console games (GTA Chinatown wars, NOVA) but they never hold my attention for very long after I buy them, they just feel like a bunch of minigames.