Robert Smith of The Cure - for me he'll always been and probably will always be the best voice in music. he's got great range for both highs, lows, and everywhere in between, conveys great emotion ranging from anger, humour, and melancholy, and his voice is truly unique. after a first few lines, you know it's Robert Smith singing.
Bruce Dickinson of Iron Maiden - the ultimate operatic heavy metal-rock singer.
Ian Curtis of Joy Division - utterly haunting voice. Bono describes his voice as "holy."
James Dean Bradfield of Manic Street Preachers - i guess there's no Manics fans here, but i think JBD is tons better than a lot of Indie band singers out there, including Thom Yorke of Radiohead, Matt Bellamy of Muse, even Liam Gallagher. he sounds aggressive and sings his great range with ease while other singers seem to strain to hit those high notes.
Liam Gallagher of Oasis - tons of sneering attitude. he doesn't need to have the prettiest singing voice or the widest range, he just does what he does best. Bono once said "if I was God, Liam would be my only son." some praise, huh?
that said, i think Noel has a much wider range though...
Bono of U2 - as much as i have a love/hate relationship with U2, i do have to agree Bono is great.
Barnard Sumner of New Order - the singer with the "I'm not a singer" voice. he sings like he only makes one take in recordings and leaves it as is, with really unique results. his voice is very boyish and innocent in many ways, and is unmistakable.