In the cartoon version of The Boondocks, Samuel L. Jackson plays a white gangsta-thug wannabe called "Gin Rummy".
This is probably brilliant. Not only is it good to hear Sam Jackson's voice, but it says something about both the character being protrayed and the job of voice acting. The significance of the casting is fully engaged with race, and so it sits square in the middle of what The Boondocks is most concerned about.