During a February, 2000 game between Marty McSorley‘s Bruins and the Canucks, McSorley delivered a vicious blow with his stick to the head of Donald Brashear.  Brashear consequently fell and banged his head on the ice, suffering a concussion and memory loss.  McSorley faced assault charges and got a hefty suspension, but the 17-year veteran never played another NHL game.  Nice way to end your career, bonehead.