Didn't Leslie Nielsen, who we think of as a comic actor today, play the title character in "Bracken's World" in the late 60's?
"The Magician" made me think of "Blacke's Magic", another blink-and-you-miss-it show about a crimefighting magician that Hal Linden did after "Barney Miller".
Some other random ones: Heather Locklear ("T. J. Hooker", Dynasty", "Melrose Place", LAX (on for about 5 minutes, but still), and "Spin City")
Jimmy Stewart (sitcom "The Jimmy Stewart Show" and drama "Hawkins")
Henry Fonda (western "The Deputy" and sitcom "The Smith Family")
Edgar Buchanan ("Petticoat Junction" and a quickie drama, "Cade's County" with Glenn Ford)
Wayne Rogers ("M*A*S*H" and "City Of Angels")
Brian Keith ("Family Affair", "The Little People", and the short lived drama "Zoo Gang")
Sally Field (comedies "Gidget", "The Flying Nun", and drama "Brothers And Sisters")
From "Happy Days": Tom Bosley did "Father Dowling Mysteries", and Marion Ross did "Brooklyn Bridge"
Do story arcs count? Then how about Alan Alda ("M*A*S*H" and "The West Wing")?
Y'all got me goin' here...
Edit: I KNEW I'd think of another one...Craig T. Nelson. Drama ("Call To Glory"), sitcom ("Coach"), and back to drama on "The District".