Forest Whitaker is similar to Yaphet Kotto and Keith David in that he's a black actor. He is dissimilar in that he doesn't possess the uniquely deep voice or the huge presence of the previous two subjects. But whereas these attributes pegged Kotto and David into the role of heavies most of the time, Whitaker has quite the varied resume playing all sorts of roles, which makes him all that more interesting to watch.
The first time I noticed him was in Good Morning, Vietnam, where he played Adrian Cronauer's (Robin Williams) pudgy, slightly geeky sidekick Edward Garlick. One of the best non-Williams lines in the film is during a scene where hate mail is read concerning the horrible radio performance of Lt. Steven Hauk (Bruno Kirby), who is subbing for Cronauer:
Edward Garlick - "From a Marine in Da Nang: 'Captain Hauk sucks the sweat off of a dead man's balls.' I have no idea what that means, sir, but it seems very negative to me."