In my head, the answer is Renly, Joffrey, Tommen, Jalabhar, and Oberyn.
But....
1. Since Anushka reminded me.... Renly is never called Prince in the books. He's always Lord Renly... even after he asserts his claim. Catelyn calls him Lord, not Prince, iirc.
2. Narky misspelled Jalabhar.
But... once again, my trivia answer is not as cut and dried as it seemed.
I'm awarding the correct answer to Anushka.