Winner: Julian Lee, congrats!
If you haven't read our review of the LG Optimus G, you should definitely check it out - this is one powerhouse of a phone. And, courtesy of AT&T, you can win one on this very page. You can also pre-order the Optimus G directly from AT&T, for $199.99 on a new 2-year agreement, at this link.
The AT&T Optimus G is packing a quad-core Snapdragon S4 Pro processor with 2GB of RAM, and I can tell you from first-hand experience that it is fast. In fact, it's easily the quickest smartphone I've ever used, and the 4.7" True HD IPS display is one of the very best I've seen on any handset.