I'll go out on a limb here. First, I am not a musician, and I am not a music expert. You probably have forgotten more than I know about drumming and drummers.
The drummer that I have been most impressed with, by far, is Billy Cobham. No question. I have seen him live back in the mid-late '70s. Back then, in my opinion, he was untouchable.
As we call know, there is no "best drummer." But I think it's fair to say that no one has better chops than ol' B.C.
Is he as good now as he was? I don't know. I have seen his two recent concert DVDs from France (which I haven't seen discussed here), and I can say that the guy is still damn good.
When it comes to lighting-fast fills, power, technique, speed, accurancy, range, influence, etc., he has impressed me the most. Plus, he's fun to watch.
If you haven't see his two best DVDs, I'd suggest:
Billy Cobham: Culturemix: New Morning Paris Concert
Billy Cobham: Live Palais Des Festivals Hall Cannes 1989
Billy Cobham's page on DrummerWorld.