Chris Roberts has, IIRC, appeared in all the main games...
WC1 - Colonel Roberts in Claw Marks and mentioned by Shotglass in one of the addons.
WC2 - He was the person 'simulated' in the CGI sequences with Blair.
WC3 - The voice of one of the Victory's escorts.
WC4 - The aforementioned Black Lance officer.
Movie - He played the Broadsword pilot who picked up Blair at the end of the movie.