Lordy Portnoy rocks...and its not all hair on fire stuff, but intricate crap, timing changes, etc. I dunno if there is a 'best', but Portnoy's set just speaks.
I saw Van Halen in Dallas last sept. Alex Played the first of Hot for Teacher for Eddies Solo. So I think he is pretty good. Sometimes though it's not how fast they can play but what kind of groove they can lay down.The drummer for ac-dc does not have a lot of flash but is a very good drummer. He gives a good lesson to other drummers about to much fill.Also Chris Layton is pretty good.