For me, nothing beats the DS. Countless hours racing my friends in Mario Kart and battling in Pokemon DP and HGSS, as well as a library pretty much unrivaled by anything else. Hell, even with all the hours sunk into it, there are still a ton of games for it that I want to get and several in my backlog. I could probably keep playing it till I'm 40 and not run out of games to play.