The Voices of "Sheldon"

Just for fun, I'm curious to see what type of voices you "hear" when you read Sheldon. Low and heavy voices? High and squeeky?

Let's list 'em out: If you had to create an imaginary cast of voices from actors and voice-actors, who would be cast to speak as Sheldon, Gramp, Arthur, Dante and Flaco?

(Cleverest response for Flaco wins an internet high-five. For example: Casting Henry Kissinger for Flaco's squees. That sort of thing.)