Tony Hawk's Pro Skater 3. It's fucking rad.
I just got X-Box Live recently, and downloaded the extended cut for Mass Effect 3, which took over 2 hours, because I still have the old X-Box 360 model.
Now, I'm replaying Mass Effect 1 using the default Shepard male model. I'm going to then import him into the next two games after that.
I also recently finished playing Assassins Creed Revelations, and I really enjoyed it.