Really depends on how beat up and understable it was. If you want super straight with slight turn and slight fade, go with a Crave. If you want even more turn, but still stable enough not to turn and burn, go with a Hatchet.
I've found it's very difficult to replace broken-in overstable discs with different molds. Maybe get a DX Teebird and throw it into some trees or throw some tomahawks until it's understable.
The gstar teebird is working great for me and its quite a bit less stable than my champ plastic birds. I really didn't expect to like it as much as I do. I'd say gstar teebird or t3