i have like 5 PSP games.. 4 of them are FFs (1, 2 and both english and JP crisis core) whilst the last one is Ridge Racer (came with my PSP bundled sale). I'd like to say I probably bought my PSP only to play FF games (just as i did for my PS3) but its really useful to watch videos and listen to music and surf the internet - VERY useful in Japan where there are free wifi zones but no computers (especially at hotels)
As for the DS, i own like.. 1 game? Mario. but i also have that peripheral that allows you to download DS games to play, so I've played a bunch of other games on it, but mostly Phoenix Wright. Didn't bother trying FFXII:RW because its so sluggish it runs worse than when I ran C&C on my 486 over a decade ago (yes, pre-Pentium era
) .
Bottom line in the portable-console war is that the DS is the more popular one and the PSP is the superior one. But at the same time, they both target different markets because the DS is so much suckier than the PSP.
To be honest, the DS is like a GBA with a built in touch-screen and some 'pocket organizer' functions.
The PSP is a full-fledged portable media device. The fact that its wide-screen, full color, stereo sound, and even supports HD (albeit 720p) is evidence of this. For certain, the PSP will outlive the DS because it isn't just a cheap novelty with GBA type games..
and i still stand by my belief that FF3 and 4 on the DS would have been 10x better on the PSP