Far Cry 2
As you can see, in Far Cry 2 at ultra high settings, the GTX 480 is definitely faster than the HD 5870 and there is no question about it. When the AF and AA comes into play, the GTX 480 definitely shows its sheer power and the difference is quite obvious at a higher resolutions.
Crysis was a game that certainly knew how to put some pressure on the GPU, and you can see that even Fermi is having a tough time with the game itself. In this case, GTX 480 is on a par with the HD 5870 and even looses when the resolution is pushed higher.
Yet again, GTX 480 shows its sheer power and it is faster than any single GPU. The difference between cards isn't that big, but after all Dirt 2 is the game where ATI's HD 5870 really shines, especially with Catalyst 10.3 drivers.