Slightly off-topic but... Several contributors to this thread have cited the voices of named vocalists as worst instrument ever.
Q magazine continue the current journalistic obsession with lists by listing the "100 greatest singers". They also (much more interestingly) list "The 10 Worst Singers of All Time".
Apparently these are:
1)Ozzy Osbourne.
2)Fred Durst.
3)Celine Dion.
4)Mariah Carey.
5)Einar Orn Benediktsson.
6)Heather Small.
7)Yoko Ono.
8)Nick Heyward.
9)Bobby Gillespie.
10)Any death metal singer ever.