Ben Browder
Ben Browder is an American actor who portrayed Isaac in the Doctor Who episode A Town Called Mercy.
Browder first came to the attention of science fiction fans when he was cast as astronaut John Crichton in Farscape, first broadcast in 1999. He appeared in every episode of the series four year run, and reprised the role in the subsequent mini-series, Farscape: The Peacekeeper Wars.
In 2003 he took the lead in the long running series Stargate SG-1. He appeared in the show's final two seasons as Lt. Colonel Cameron Mitchell, and returned for the two spin-off television movies, The Ark of Truth, and Continuum.
Browder also had a recurring role in Party of Five, and has guest starred in Murder She Wrote, Chuck, and Arrow.