The best enforcer should also be the most intimidating, otherwise he's not that effective.
I go with Dave Brown here. He could not (IMO) play NHL level hockey, but still made a pretty long career by scaring the crap out of opponents by just sitting mostly on the bench. Brown did not much care about "the code" and that made him more intimidating than some other enforcers with similar fighting skills.
Bob Probert was probably even better (or at least equal) fighter than Brown, but I don't think Probie was feared as much as Brown was. Even some other enforcers admitted that they feared Brown who could destroy orbital bones with his lefts.
Dave Brown was not a "good cop", like say Laraque. Brown was a genuine, mean SOB who could really hurt you any time and did not give a damn. Beating the opponents heavy weight to a bloody pulp or brutally by cross-checking star player in the face. Dave Brown would go after anybody.