Normally I'd say pick up the Wii for a whole better variety considering PS360 share so much in common. However, you take out the biggest (and best) option for games on Wii when you say you don't like Nintendo games. Personally, I don't see how anyone can honestly not enjoy a Nintendo IP, but that is neither here nor there. So, if that is really the case then its obvious a PS3 is your only real choice.
Then you can choose between the consoles depending on if you HAVE to play on live for certain friends or if the free PSN and your friends on there are just as good. Maybe drop XBLive at some point even. I guess that depends on your friends on both systems and if you really use all the other content XBLive offers. Personally the rest is free for me through the PS3 Browser, but that's just me.
