If people actually give reason(s) for their choice, this thread won't need a lock.
That said: DSi has a slight edge on the PSP. The PSP trumps on stuff like graphic quality, music, video, but is much weaker on software. The DSi has a touch screen and better battery life, but could use some incentives for older gamers.
PSP has gaphics things and bla bla bla, who cares, i prefer the touchscreen and simple games than a stupid normal: screen with better graphics and a crappy batterylife, and Sony sucks
DSi pwns the PSP and any PSP2, PSP3 or whatever will beat the 3DS, now the PSP is just dead, dead deaaad
The bed is a factory. A factory of dreams, and a factory of babiess!!