Originally Posted by Soundwave
If the only thing you're ever going to play is sports games (which are multiplatform) and want to be able to watch high def movies, then yeah go with the PS3. The same sports games will be on both systems.
Make sure you get the Blu-Ray remote control with it though, flipping through menus using the controller is a pain.
The only thing is the 360 can play HD movies too via the HD-DVD player add-on, but at the moment it looks like Blu-Ray might win the format war. The whole HD movie business is a bit of a mess to be honest.
The PS3 as a system is much more reliable in terms of hardware (won't break as often) and runs quieter and cooler than the 360. If you're getting a 360 I wouldn't touch one off eBay with 20 foot pole, especially one without warranty. Make sure you get a brand new, unopened one from the store.
Just to add an opinion, I think the 360 breaking dilemma was blown out of proportion. Sure some people got the red light of death but others like me and my friends have had working 360's since 2006/2007. If you buy a 360 make sure its one of the newer models and not one from 2005.