Personally I put with a Star Classic Roc - but these are only tournament discs and are hard to get a hold of. I find this disc to have a medium stability and great grip. This disc is personally responsable for the best putting of my life, and since it has been in the bag, putting in the wind has been a beeze (um, bad pun I know). I also won my first pro tourney since putting with a Classic Roc.
The champion classic roc is very stable and is one of my main approach discs. For backhands and sidearms alike, this disc goes where I want it.
I also have a stack of DX discs that make appearences now and then. They are stable as well, almost more stable than their champion counterparts.
I haven't thrown pro in a while and currently don't have any.
Which plastic do you use and how has it improved your game?