It's a good question. Probably none. If you put something at 100 then you have NO room for improvement, and that's just not possible. 98 or 99 would be quality belgians like St Bernardus Abt 12, Gulden Draak, or a good IPA like Pliny the Elder or a good barleywine/strong ale like Arrogant Bastard. So many good beers out there, but none is 100.