From the Carry On… films: Kenneth Williams and Barbara Windsor.
Arianna Huffington. I used to listen to her on Left, Right & Center (a political discussion program on public radio) during the 90s. When I first heard her voice coming out of that bear on “The Cleveland Show” I just about pissed myself.
(Even though she had that gig, she might not count as an actor, though)
Did anyone mention Rowan Atkinson yet? I mean, his silent work as Mr. Bean is hilarious, but his speaking roles as the priest in Four Weddings and a Funeral and the boutique guy in Love, Actually are to die for.
Speaking of which: William Daniels is exactly what a car’s artificial intelligence would sound like if it were talking down to a male model sporting tight jeans and a big perm.
(I grant that he also sounds like that at other times, but it remains true.)
Paul Bettany as Vision/Jarvis and also John Nash’s friend in A Beautiful Mind.
Christopher Lee.
As a kid, I was quite impressed with his voice in Journey To The Center Of The Earth. And took to imitating him (Since I was only six, I can guarantee no one had any idea what I was doing, so… I stopped).
As an adult, I started reading the first Harry Potter book to my kids. I needed a good Dumbledore, so I imagined what an elderly James Mason would sound like.
William Daniels, despite being raised in Brooklyn, uses a Brahmin-esque accent, most of the time.
Andy Devine. Nobody really like him,–except for maybe Slim Pickens, but Andy was a gentler sort. Slim had a similarly distinctive way of of speaking, seemed edgier; real world, sorta. Andy was All Hollywood All The Time.
The other Brit of Caine’s generation, Sean Connery, had a voice he probably couldn’t have hid if he tried to.
John B.
I moustache you a question, but I’m shaving it for later.