I love talking 'bout who's best drummer. First of all, the best in the business are Steve Gadd, Harvey Mason, Vinnie Colauita, Steve Smith and Simon Phillips. Regardless of the genre, these guys are at the top. Without a doubt, Neal Peart, Mike Portnoy, Terry Bozzio, Prairie Prince and don't forget a cat named Richard Bailey are awesome and should be on anybody's list of the best.
Now if you want to talk about the younger dawgs that kill it you've got to check out Josh Freeze, Ronald Bruner, Jr. (scary!), Antonio Sanchez, Russ Miller, Stanton Moore, Brooks Wackerman, Adrian Young and Atom Willard. These guys have incredible chops!
The problem(?) is that there are so many great drummers that it's almost impossible to answer the question without a long list.
The great thing is that we get to enjoy them all and learn from them.
Keep the groove on!