Considering that I have been questioned (both online and off line) about several of the choices on my best living musicians list, I felt that I should take some time to address these concerns.
While Dave Gahan sings lead in most of Depeche Mode’s songs – which works exceedingly well for their music – Martin Gore has a better voice in my opinion.
I realize that Lindsey Buckingham mainly plays guitar, but he also plays bass which makes him a bassist as well. He also sings lead vocals on some songs, using the same logic it could be argued that he is a singer not a bassist. This is flawed reasoning, an individual can wear many hats and his shear flexibility in playing styles and versatility in roles makes him phenomenal.
As Garg Unzola stated in his comment, there are vocalists with better singing voices than Dave Mustaine, but he uses his voice in ways that I have heard no one else do. He is able to perfectly express a large variety of emotions while still being perfectly understandable.
Other questions are certainly welcome, and will be addressed in the comments of this posting.