Do voice actors count??
Leonardo DiCaprio
Why: That man sure has some dedication and determination
David Wittenberg (VA) - Naruto (Kakashi Hatake), Ghost In The Shell (Saito), Dragon Hunters (Hector)
Why: A lot of voice actors speak with the same voice for every character but David is one of the few that can change it up quite a bit (compare characters like Kakashi and Hector for example.
Mike McFarland (VA) - DBZ (Master Roshi, Yajirobe, & various other characters in the series), FMA & FMAB (Jean Havoc), OHSHC (Ryoji Fujioka)
Why: Similar explaination as Wittenberg; can change his pitch to go with the character he's voicing. Also he's a bit of a jack of all trades in voice acting department. He's an ADR director for a lot of animation done by FUNimation as well as a script writer, voice director, etc. It has to be difficult to voice a character and having to direct yourself instead of someone else directing for you during your scenes all at once. That is some dedication and multitasking there.
"Never forget what you are, for surely the world will not. Make it your strength. Then it can never be your weakness. Armour yourself in it, and it will never be used to hurt you."