WiiStation360 on 27 April 2009
Just make a list of the non-PC games on each system and pick the ones that are most appealing to you.
Keep in mind:
PS3: More expensive, but free online play. Lots of great non-PC exclusives coming this year. Great Blu-Ray player
360: Hardware quality should not be a issue anymore. But still a yearly fee for online. Netflix streaming, if you are a netflix & XBLive Gold member.
Wii: Many great unique games, but graphics are not as good as what you are used to on the PC. Probably the only console you girlfriend will play with you.
