9. Michael K. Williams
Episode: Season Three, Army of One One of the stars of the other HBO masterpiece The Wire briefly appears in an episode towards the end of Season Three. When Jackie Aprile, Jr. foolishly attempts to rob one of the executive card games, things go horribly wrong and Jackie Jr. must take shelter with Williamss character and his young daughter. The appearance was hardly a career breakthrough mainly due to Williamss miniscule screen time but Wire fans could not mistake the actors formidable presence mainly due to the actors real facial scars. Like Arnett, Williams also appeared in a number of US television dramas in the early stage of his career such as Law & Order and Alias. Similar again to Arnett, he would not have to wait long for a recurring starring role. The following year Williams was cast as Omar Little in The Wire. Omar is one of the most iconic characters in the series and was a series regular throughout the shows five season run. The character who is a daring thief and who is also gay was even the personal favourite of US President Barack Obama despite his violent criminal behaviour. Williams now stars on Boardwalk Empire as Albert Chalky White which is developed by former Sopranos writer/producer Terrence Winter.