I've seen all the X-Files episodes. But now seeing the Millennium episodes, there's like an actor or actress in pratically every one or two episodes that played in an X-File episode.
Jose Chung (Doomsday Defense) - Jose Chung (From Outerspace)
Peter Watts (main star) - Lt. Brian Tillman (Aubrey)
Henry Black (Midnight of the Century) - Arthur Dales (Augula Mal)
Danielle Barbakow (Monster) - Emily Sin (Christmas Carol, Emily, All Souls)