Depends on what your goals are.
If you are wanting to game at the highest resolution / frames you can, then you would want the best GPU you can get.
If you are more of a counterstrike guy who games at 1080p and wants the highest FPS possible, a more budget card works, with an upgraded CPU to drive the performance.
If you are interested in bang for your buck, that could be a different choice.
What monitor are you currently using? What types of games or work are you doing?>