Art blakey is one of my favourites, but just feel Peart has it all, timing, groove, syncopation, and it's effortless, have a look at the new live in rio cd, extra disc has umpteen view thingy just so you don't miss anything, mesmerising his solos are not boring so that even non drummers like them, FWIW Peart is first and foremost a jazz man and BR is his hero, there styles are quite similar, the man is a drumming god, not familiar with all the jazz drummers mentioned as my tatse lie mainly up to now in rock, but Peart is the best I have heard, by a long long way, and when he plays jazz stuff, he would surprise a lot of you jazz fans, his timing is sublime and he is so musical as a drummer, bear in mind that Rush don't have a seperate percussionist, and do very little overdubs (if any the odd track but never more than one/album, and thats usually keyboards), his recognition problem is that a lot of people don't like Geddy Lee as a singer and so don't listen much to rush and he does very little other stuff.
Peart is the best, you're all deaf if you disagree, I've been taking lessons from James and I'm right and you are all wrong
EDIT think i mentioned Krupa, but I prefer Buddy, more energy, ian paice is another pretty good rock drummer, have also heard mel gaynor in the studio and he is metronomic in his timing, good but not one of the greats.