Here is my incomplete list. As I'm a child of the 80's and 90's it is weighted that way. I'm sure there are more that you guys will advocate for.
Chris Cornell (Soundgarden. Audioslave, Solo)
Thom Yorke (Radiohead)
Brad Delp (Boston)
Steve Perry (Journey)
EDiT: Sorry hit enter before done, more complete list continues
Robert Plant (Led Zepplin)
Freddie Mercury (Queen)
Have at it. Who else belongs here?