Don Cheadle – Ocean’s Eleven (2001)

Don Cheadle plays Basher Tarr, an explosives expert with a heavy Cockney accent. With how awesome Ocean's Eleven is, Cheadle's attempt at a Cockney accent sticks out like a sore thumb—it's enough to make you cringe. There are even moments in the movie when he loses his accent, and falls back to his American one. Don't get me wrong, Cheadle is a great actor, with his performance in Hotel Rwanda (2004) even earning him an Academy Award nomination, but his performance in this movie feels more like an impersonation.