The best is gotta be the rolling drums. Cannibal Corpse is awesome for that. But the best drumming I've heard so far is definitley Morbid Angel - Drum Check. Vocals vary, it all depends on who it is. I don't really like the low pitch growling but the high pitched growling is good. Agony Scene I think has good vocals. Sometimes, tho, i like to be able to understand what they're singing, then you have to pick doom metal. November's Doom and My Dying Bride are awesome doom. Its sometimes kind of depressing, My Dying Bride is freaking slow and gothic, its great. I have only started listening to metal about 2 months ago, but it clearly kicks ass. My friend Ow3n turned me onto metal, and you can visit his site
www.MansionofMetal.com