A friend of mine says Neil Peart of Rush is the best. But after seeing some videos, I dont quite agree.
Best drummer is really quite subjective. Personally, I like Dave Grohl.
I think it really depends on the genre of the music. If its heavy metal for example, there is only one speed on the drums, the drummer is just pounding away on the double bass, toms and snares non stop. because a group like Fleetwood Mac encompasses ballards, rock, blues, blues rock, etc. the drummer has to change his pace and style to fit the particular song. More challenging in my opinion. U can see Mick Fleetwood really working the drums like crazy during the fast numbers, and than take it down to almost dead slow in "Landslide". That's why I think he is the best, and perennially on Playboy's All Star Band.
As for Max Weinberg, a bespectacled Jewish boy from New Jersey playing drums for one of the Greatest bands in history is just an incredible story.
As for David Grohl, i don't consider any of them (Nirvana) a musician at all. I am not even sure you can call him a drummer as he also plays piano, guitar, bass, etc on his own albums. In fact, his set of drums in Nirvana would not cut it for most professional drummers, u are talking about one snare, one tom, and one bass, plus a whole bunch of cymbals? I don't think he is a dedicated drummer at all.