I've got a fat PSP, 1st gen, running 5.00 M33-6. I absolutely love it. I play a lot of older Lego games, Crisis Core, Tekken 6, Hot Shots Golf 2, etc.. I also have 1 PSX game, Tekken 3 that runs perfectly.
Having said all that, I want to play the new Final Fantasy IV, but am pretty sure it...