PS2 for me as well. I am very biased though as I have been playing patched PES4 for ages and the only time I ever played X-Box PES4 it wasn't patched and the controller was huge and I got pissed off with it after 5mins!
I also think the PS2 gives the X-Box a very good run for it's money graphically and that the gameplay on PS2 seems smoother and more responsive.
I have, and never will, play a game on a PC. I have a deep-rooted hatred for any kind of gaming on PC's. I don't know why, I just do. Keyboard my arse..........