When I first started writing about 15 years ago I heard the market did not take kindly to novels in which the characters were either singers or sports personalities. That's because for some reason apparently people didn't like reading about them.
I broke that rule in 2006 with my debut mystery, Two Wrongs, about a pro basketball player, though he wasn't one at the beginning of the book. I know I'd read a book about a singer if the plot sounded interesting. I enjoy books about people in almost any kind of occupation, but especially ones of power where I can experience that feeling vicariously.
What about you? What are your favorite or unfavorite jobs for book characters? Would the main character's job stop you from reading a book?