xbox has way better service than ps3 thats why you have to pay for it, i would better games, better online service and the controllers are more comfortable
XBox live is good, but the fee is bothersome. Other than that don't try and say it has better games because the only 2 games I can think of that XBox has that PS3 might want is HALO 3 (which is not even a good game) and GOW. Here is how it generally will be whether you have both systems or not;
If you bought the PS3 first then buy an XBox you will favor the PS3 (GENERALLY NOT ALWAYS) and vise versa for the XBox.