No order:
Bruce Soord - The Pineapple Thief
Tommy Rogers - BTBAM
Thom Yorke - Radiohead
Jonsi Birgisson - Sigur Rós
Simone Simmons - Epica
Jørn Lande - ARK, Ayreon
Jonas Renkse - Katatonia, ARK
Mikael Akerfeldt - Opeth, Bloodbath, Ayreon
Russen Allen - Symphony X
James LaBrie - Dream Theater, ARK
Roy Khan - Kamelot
Tarja turunen - Nightwish
Bruce Dickinson - Iron Maiden
Claudio Sanchez - Coheed and Cambria
Steve Wilson - Porcupine Tree, No-Man, Blackfield
Daniel Gildenlöw - Pain of Salvation, Ayreon
Neal Morse - Spock's Beard, Transatlantic, Solo
Yeh that's more than ten, so shoot me.
Why the hell are people listing the Lamb of God and Metallica singers? I mean come on...
Edit: Whoops, forgot good old Billy Corgan