In terms skill with his part of the band (i.e instrument vocalist): Daniel Gildenlow.
He is simply the best vocalist ever, and he is a damned good guitarist as well. <3 him.
In terms of showmanship.
Daniel Gildenlow. (Watch the BE dvd to see why)
Kurt Kobain (Nirvana)
Jimi Hendrix
Lemmy Kilmister (Motorhead)
Bruce Dickinson (Iron Maiden)
Feddy Mercury (Queen)
Bob Marley
Mick Jagger (Rolling Stones)
Ozzy Ozbourne (Black Sabbath)
Jonny Rotten (Sex Pistols)
Pete Townshend (The Who)
Jimmy Page (Led Zeppelin)
Marilyn Manson
Dave Grohl (Foo Fighters)
Ville Valo (HIM)
Brian Johnson (ACDC)
Mike Patton