XBOX360

Built Quality - Looks great and very well built (except for 3ROD problems with earlier model). The power brick is big! Fan noise can be heard.

Controller - Looks and feel better than the DS3. Trigger button is fantastic for FPS. I really like the middle XBOX button where we use it to turn on/off the 360. To turn on,you need to hold it instead of the PS3 which just need to push it which is very prone to accidentally turn on the system. No such problem with the 360 as you need to hold for a second or 2 to turn on the 360. I i love the cool lights on the logo. Use AA battery which can be easily replaceable....big plus!!!

Multimedia capability - No Bluray. All the rest should be similar. Custom soundtrack in games

Online - XBOX Live is no brainer but its not free though. 360 really kicks PS3's ass here.

Play backup games - YES

PS3

Built Quality - Great and no 3ROD problems. Good looking but I still prefer the 360's overall look.

Controller - DS3 is quite boring to look at compare to the 360's controller. Sixaxis is bullshit so far. Built in battery is gonna die eventually and lead to expensive replacement. D-pad is better feel though.

Multimedia capability - Big plus for Bluray. So far no custom soundtrack for games yet.

Online - Free but not as versertile as the LIVE.

Play backup games - NO