Yer joking, yes?
Hermaeus Mara from the quest Discerning the Transmundane. He sounds like Sean Connery.
Maybe a cross between ol' Sean and Elmer Fudd.

Sounds like a character from a bad children's movie: "Mah tongue ish shtuck to da ROOOOF of ma moowwwth." Puts me to sleep.
OH for God's sake where is Karliah so I can go talk to her.
You'll have to get dirty in Riften to find her (err, that's a hint).
Ulfric - talk about someone who puts me to sleep! Although, I suppose he's supposed to always sound like he's half-asleep - running a revolution is so tiring!
Tullius - I jumped when he first spoke! Really type-casting there, but it was funny for a while!
Belethor - must agree - makes my skin crawl just walking in his store.
Cicero - I love me some Cicero!

Best follower ever!
Delvin - Dead-on perfect for the role. Even if I don't join the TG, I'll go down to the Ragged Flagon just to talk to him.
Fralia Gray-Mane (and just about every other older lady with the same voice) - some of the things she says literally bring tears to my eyes.
Barbas - I love to hate this voice! OMG, whose idea was this???? Vigilance never talks like that!
sigh...