Both systems have the same abilities. 360 has better graphics in a side by side comparison. Ps3 doesnèt have the exclusives that make you want to trade in a 360 for it. Wii has one good game, and it comes with it (unless you are looking to spend money to download games you can get as roms on the computer).
The only option I see is simply get an upgrade for your computer. I play 360 games on my Pc and they run better than they do on the 360.
P.S. The Ps3 online hype is a bunch of bull****. Players can barely play games, cant find friends and the system is broken. At least Live is stable, but that is also a money waster in itself.
Edit:
http://www.escapistmagazine.com/arti...onsole-Rundown
sums it up pretty well