Speaking solely on the sound and pitch of the voice, not accents:
I hate any high pitched voices on adults. If you had to answer the phone and the person on the other line says: " hi sweetheart, can you give the phone to your mummy," then there's a good chance I'm going to hate your voice, no matter how famous you are.
One of my least favourite celeb voices is Adam Levine (spelling?) from Maroon 5. I have to turn off the radio when he sings, how did he become lead singer? Justin Timberlake is another one, too high pitched when singing. Michael and Janet Jackson's chronic whisper (when speaking) gives me nightmares.
I like Princess Eugenie's, and James Lock's.