Two that most haven't heard of, i think.

Jon Hiseman (Colosseum)

and Simon Phillips (he played with just about everybody)

Dave Weckl is a monster, primarily jazz though.

Probably a relative unknown, but Sean Reinert is absolutely awesome. He played with a band called Cynic in the early 90s - their "Focus" record has some of my favorite metal drumming ever on it.

He went on to play with Aghora and some of the Gordian Knot stuff, none of which approached Cynic's awesomeness.

Johan Langell, original Pain of Salvation drummer, was great too. Like a tasteful Mike Portnoy.

Chris

I forgot about him! He is pretty good. I like his youtube videos a lot.

probably Mitch Mitchell or Mike Portnoy, different areas of rock, but they were/are maters at what the did/do

When it comes to the drum sound, Mitch Mitchell is a favourite of mine. If that makes him the best drummer, I don't know.

well one of my top3 favs goes to Carl Palmer

Carl Palmer played in Emerson Lake and Palmer and played some really hard stuff

i always admired his speed and complexity, and he got me into prog rock

Mitch Mitchell is quite amazing and vastly underrated, well he's esteemed pretty high by those that looked beyond Jimi's guitar work. Don't get me started on Noel Redding.

Mike Portnoy. He possesses so much talent and is amazing live.

I always dug Mitch Mitchell. When I was a kid, the drums on "Manic Depression" seemed impossibly hard, but that was before I could really hear what he was doing. Definitely one for all times.

And Noel Redding, of course, was my first favorite bassist. Probably because The Experience was one of the first bands I ever got into. He was kind of a fashion bitch, though. At least that's what some of the stories make him out to be.

J.H.E. R.I.P.

I never thought of Mitch Mitchell being at all underrated and is normally in most peoples great drummer`s list (certainly in mine). Like Noel Redding who is a great bass player, they played with Hendrix probably the most revered rock musician in the last 40 years or so. Everbody knows Hendrix, whereas only those in the know remember the other two, both of whom were vital ingrediants to the JH.Experience.

While speaking about Mitch Mitchell, another classic drummer of that generation and time was certainly Mike Shrieve (Santana) His performance on Woodstock was one the festivals major highlights.