Tom Kane

Tom Kane provided the voice of Commissioner Gordon and Mayor Quincy Sharp in both Batman: Arkham Asylum and Batman: Arkham City

He is uncredited for voicing Louie Green in Batman: Arkham Asylum, but he's credited for voicing the Spirit of Arkham/Amadeus Arkham.

Trivia

 * Also known for his work in the Marvel Comics, he voiced mostly villians than heroes, but in the DC Comics, he voiced mostly heroes than villains.