Laura Bailey (Soul Eater - Maka/Fullmetal Alchemist Brotherhood - Lust)
George Newbern (Final Fantasy VII - Sephiroth/Justice League - Superman)
Todd Haberkorn (Soul Eater - Death the Kidd/Fullmetal Alchemist Brotherhood - Ling)
Mark Hammil (Batman - Joker)
Vic Mignogna (Fullmetal Alchemist - Edward/Dragon Ball Z - Broly/Soul Eater - Spirit)
Laura Bailey (Shin Chan) - as Shin Chan
Christopher Robin Sabat (Shin Chan, DBZ) - Yonro, Piccolo and Vegeta
PLUS anything with James Earl Jones. Darth Vader...
Kevin Conroy as... y'know ! :wink:
Maurice Lamarche.
Of those still living and working today, I'd say Frank Welker, voice of more characters than I can name, including Freddie from Scooby Doo, Megatron and a bunch of other Transformers, various non-speaking animals, horny young Spock in Star Trek III and many many more.
Also Peter Cullen, who is mostly known for Optimus Prime, but just has an awesome "movie trailer" voice.
http://www.youtube.com/watch?v=Wp3P5cAOM6A