Kantor on 09 January 2009
Xbox Live is by far the best. Server quality is slightly better, and Xbox Marketplace is better than PS Store.
On the other hand, PSN is free. It's not bad at all, it's a very good online service. For what you pay (nothing), you get a well-stocked store, and mostly very stable servers. If you were to compare them in terms of quality/price, PSN would win (obviously)
Wii Online... no comment. I don't know anything about it except that it's free and is not as good as Live/PSN.
(Former) Lead Moderator and (Eternal) VGC Detective 
