Awesome bang for the buck, looks great, and doesn't take a ton of power to get you some good FPS. I've been avoiding Nvidia for 5 years now, due to tons of problems I had with the 8xxx and 9xxx series crap.
I love the value you get from AMD. Dollar for dollar, you get more with Radeon graphics. Look at the latest driver release, these cards are so powerful that they are still unlocking more out of them. I'd love one of those 7770's to upgrade my old nvidia gtx460.
The thing i list most about AMD brand cards, especially this generation is their ability to play all of the latest titles off the shelf, their drivers have gotten better recently and their ability to do things better than Nvidia (Only thing that comes to mind at the moment is Bitcoining).