I own a 360 and I have Call Of Duty 2 (Amazing game) and Perfect Dark Zero (I think it's cool but nothing special). I've played the demo of Fight Night Round 3, its unreal. When you knock a guy out after he hits the ground it shows a replay of the punch and you see spit and blood sometimes come out of the opposing boxer's mouth (drools).
So far I love the 360 but it is lacking a good amount of titles that interest me. Once Fight Night Round 3 comes out I'll pick that up.