5850 is the way to go. The 5770 struggles to play games that are out right now at smooth fps at 1900x1200 res. It can't even play dirt2 super smooth at 1900x1200 res, which uses dx11. Some people like to crossfire te 5770 to get great performance for the $, but some games still don't recognize two graphics cards.
5850 for the win baby.