Two words.... elite controller.... I know they are expensive and I was against them at one time until I gave in and bought one... so nice having the extra paddles to map buttons. I now use a modified halo 4 layout. It's awesome.
As much as I'd love to agree, I've had two Elite controllers break on me. The left thumbstick stopped clicking on my last one, so I got it replaced. And today, my left bumper button has come loose, further examination shows that it's broken inside.
Further research shows that it's quite a common problem, with multiple threads around the internet. They make the bumper buttons with cheap plastic and they eventually fail.
This video shows exactly the same problem that mine has.
For what it's worth, the Elite controller was awesome when it worked, and being able to use the paddles definitely improved my game. I'm just wary about buying a third one, and am thinking of maybe trying the Scuf controllers out. Anyone here using them? Any other pro controllers?