Here's some of his notable TV guest apperences (curtosy of
http://www.imdb.com):
"Baywatch Nights" (1995) playing "Dr. Lancaster" in episode: "Frozen Out of Time" (episode # 2.13) 8 February 1997
"Spider-Man" (1994) playing "Spencer Smythe" (voice) in episode: "The Spider Slayer" (episode # 1.3) 4 February 1995
"Hotel" (1983) playing "Franklin Danforth" in episode: "All the King's Horses" (episode # 4.22) 27 May 1987
"MacGyver" (1985) playing "Guy Roberts" in episode: "Three for the Road" (episode # 2.10) 15 December 1986
"Murder, She Wrote" (1984) playing "Julian Lord" in episode: "Stage Struck" (episode # 3.10) 14 December 1986
"Murder, She Wrote" (1984) playing "Richard Bennett" in episode: "One Good Bid Deserves a Murder" (episode # 2.17) 23 February 1986
"Matt Houston" (1982) playing "Malcolm James Abicromby (Brigadier)" in episode: "Whose Party Is It Anyway?" (episode # 1.15) 23 January 1983
"Hart to Hart" (1979) playing "Arthur Sydney" in episode: "The Man with the Jade Eyes" (episode # 1.11) 11 December 1979
"Battlestar Galactica" (1978) playing "John" in episode: "Experiment in Terra" (episode # 1.22) 18 March 1979
"Hunter" (1977) in episode: "Bluebird Is Back" (episode # 1.1) 18 February 1977
"Ellery Queen" (1975) playing "Myles Prescott" in episode: "The Adventure of the Two-Faced Woman" (episode # 1.18) 29 February 1976
"Streets of San Francisco, The" (1972) playing "Cabinet Minister Brian Downing" in episode: "One Chance to Live" (episode # 3.6) 17 October 1974
"Cannon" (1971) playing "Neal Ray" in episode: "Death of a Hunter" (episode # 3.20) 13 February 1974
"Streets of San Francisco, The" (1972) playing "Amory Gilliam" in episode: "Tower Beyond Tragedy" (episode # 1.5) 28 October 1972
"Custer" (1967/I) in episode: "The Gauntlet" (episode # 1.15) 20 December 1967
"Daniel Boone" (1964) playing "Colonel Burton" in episode: "Secret Code" (episode # 4.13) 14 December 1967
"Cowboy in Africa" (1967/II) in episode: "The Man Who Has Everything" (episode # 1.13) 4 December 1967
"F.B.I., The" (1965) playing "Major Damian Sava" in episode: "The Hostage" (episode # 2.22) 19 February 1967
"Twelve O'Clock High" (1964) playing "Col. Schotten" in episode: "The Duel at Mont Saint Marie" (episode # 3.14) 23 December 1966
"Run for Your Life" (1965) in episode: "The Savage Machines" (episode # 1.29) 2 May 1966
"Twelve O'Clock High" (1964) playing "Kurt Halland" in episode: "Siren Voices" (episode # 2.29) 4 April 1966
"Convoy" (1965) playing "Captain Kurt Von Krug" in episode: "The Duel" (episode # 1.6) 22 October 1965
"Daniel Boone" (1964) playing "Col. Marcus Worthing" in episode: "Empire of the Lost" (episode # 2.1) 16 September 1965
"Daniel Boone" (1964) playing "Admiral Lord Clydesdale" in episode: "The Ben Franklin Encounter" (episode # 1.23) 18 March 1965
"Farmer's Daughter, The" (1963) in episode: "Katy and the Prince" (episode # 1.23) 26 February 1964
"Mr. Novak" (1963) in episode: "He Who Can Does" (episode # 1.15) 31 December 1963
"Outer Limits, The" (1963) playing "Professor Mathers" in episode: "The Sixth Finger" (episode # 1.5) 14 October 1963
"What's My Line?" (1950) playing "Guest Panelist" 17 March 1963
"United States Steel Hour, The" (1953) playing "Algernon" in episode: "Who's Earnest?" (episode # 5.3) 9 October 1957
"Kraft Television Theatre" (1947) in episode: "The First and the Last" (episode # 10.42) 10 July 1957
"Studio One" (1948) in episode: "Eight Feet to Midnight" (episode # 9.29) 29 April 1957
"Kraft Television Theatre" (1947) in episode: "Night of the Plague" (episode # 10.27) 20 March 1957
"Adventures of Robin Hood, The" (1955) playing "Ulf" in episode: "Blackmail" (episode # 2.3) 15 October 1956
-Knight Rider 2000