^I believe all PS3's being manufactured now lack the Emotion Engine, and can't play PS2 games.
To the OP, I would look at lists of games available for the systems and see which one has the games you want. I think PC is the true way, but I'm looking to get a PS3 or Wii personally. IMO the Xbox has way to little exclusive software, It's a matter of time before Halo 3 and Gears 2 are ported to the PC, even if Epic and MS are saying it won't happen(like before)
I'm leaning toward the PS3, I'v never found the Wiimote all that fun to wave around, and after the endless flood of peripherals that was nintendo for the past 10 years, I'm kind of want a plain controller. They still owe for that 10-kiloton fusion bomb that was the e-reader.