NCChiFan
Argumentum artifex
Buddy Rich.
Almost every single drummer I've ever known says Rich was the man. Everyone else falls in line behind him.
A bit biased (huge Vandals fan), but I'll go with Freese.
Dave Grohl, no question. What dave did on a 5 piece kit in Nirvana was mindblowing. You watch the Paramount video, he is killing that little kit.
His playing Rock and Roll at Wembley with Jimmy Paige and John Paul Jones even impressed Jimmy.