Drummers is a hard one as there's too much emphasis on technical drummers, or those that play very fast. I think as I've got older I've tended to appreciate the subtleties of drumming more (not something I have in my own drumming...
I think over time I've got to appreciate Ringo Starr's drumming much more - while there's nothing flashy about his drumming, his timing is impeccable and I doubt that the Beatles would have had exactly the same sound without him. I think it was George Martin talking about how great his timing was and saying that when the original masters were digitized they put a lot of the early tracks that were recorded live alongside a click track and discovered that the songs rarely went out of time by more than a fraction of a second per minute.
Jaki Liebezit of Can is also a great drummer. That driving beat is really hard to maintain and I think he set the pattern for a lot of other drummers who did the same thing later.
Then there's the likes of Gene Krupa or Keith Moon who loved to be the showman on the drums, something that's pretty hard to do unless you have the personality to back it up.