Queen Ayrenn, Elam Drals, (someone said they could listen to them read the phone book, yes, that's how it is with Elam for me.) Razum Dar, Bil Nighy, Sotha Sil (the slowness of his speech!) John Cleese. So masterful. The count in the Reach.
My first voice love when I started playing was of course The Prophet.
I was watching Harry Potter with my Grandkids and Dummeldore's voice ... it kept ringing in my head with a crazy familiarity, then I realized it was the voice of the Prophet! That was really cool.
Also, the very very monotone voice of the argonians that pop up here and there, quite unique although not one I could listen to for long periods.