I will go with the majority here that it best to buy a PC Version.
Three reasons for this:
1) Its cheaper since it doesn\'t have the hard-drive. Even if Square is willing to sell it $75 combo, it still a little pricey for me.
2) It have a much higher resolution than the ps2 version, it can display 1024 x 768 which improve details and higher refresh rates.
3) I think it easier to play it on computer than ps3. You can use the keyboard to type message...i guess...not sure...while ps2, you need a keyboard and that mean $$? either way, i still feel pc online is better.