I am going to have to go back in time and say that I wish Marino and Tarkenton (sp?) could win their rings. They were both great QBs that could never win a championship. I would mention Barry Sanders, but I feel like Barry just kind of gave up on football. The man was about 1400 yards away from breaking the rushing yards record and could have easily done so, but he just said "Meh, I'm done...too easy." so he shot himself in the foot there.
Also, all the current Packers who have yet to win their rings...but that goes with out saying!