The SP, easily. My recent purchase of a DS has only affirmed that decision. I bought the DS because I could no longer deny the amount of great games coming out on it, but as a "portable" system, the design sorta sucks. I like that it's a clamshell system, but it's thick, bulky, and not exactly all that comfortable to hold. The PSP fairs better, but the analog nub is in a crap position and has way too big a dead zone, it smudges like a mofo, and is the size and weight of a last-gen PDA. The SP is small, but comfortable to hold when opened, can protect its own screen, and doesn't look like a bizzare rectangular boner when thrown in your pocket. I carried my SP around with my everywhere, the DS has been abit of a pain at times. A handheld designed system should, by its vary nature, focus on portability. These present-gen portables focus on functionality, but give us bricks in terms of form.