LAST UPDATED: November 7, 2016. Info derived from the imdb. Only titles 2014-on noted by name. Only actors in 3+ episodes (some in 2 episodes) and the opening titles narrator (technically most episodes Archive) noted.
David Hasselhoff (Michael Knight): in Call of Duty: Infinite Warfare (2016 video game), Sharknado 4: The 4th Awakens (2016), Trip Tank (2 episodes 2015-2016), Last Night a DJ Saved My Life (2016), Alleluia! The Devil's Carnival (2016), Sharknado 3: Oh Hell No! (2015), Kung Fury (2015), Newsreaders (3 episodes 2014-2015), Stretch (2014); Baywatch (2017) in post-production; Power Play (2016) filming; American Paradise (nd) in production; as Producer: Hoff the Record (6 episodes 2015; 9 2015-2016 as Writer, 12 as Self); as Executive Producer: Last Night a DJ Saved My Life (2016); as Producer/Self, completed: Killing Hasselhoff (2015); as Self: Talent Suomi (4 episodes 2016), WGN Morning News (1 episode 2016), Gotham Comedy Live (1 episode 2016), Good Morning America (1 episode 2016), The View (1 episode 2016), The Big Interview with Dan Rather (1 episode 2016), Access Hollywood Live (1 episode 2016), Entertainment Tonight (3 episodes 2014-2016), This Week in Hollywood (1 episode 2015), Loose Women (2 episodes 2015), Pride of Britain Awards (2015), David Hasselhoff Show (10 episodes 2015), American Idol (1 episode 2015), B-Movie: Lust & Sound in West-Berlin 1979-1989 (2015), LeagueOne: In the Spotlight! (unknown episodes 2014), Strictly Come Dancing (1 episode 2014), Screen Machines (1 episode 2014), The Insider (1 episode 2014), MTV Europe Music Awards 2014 (2014), Brändärit (1 episode 2014), I'm Will Ferrell (2014), Hasselhoff vs. The Berlin Wall (2014), Hasselhoff - en svensk talkshow (10 episodes 2014), Unusually Thicke (2 episodes 2014), Só Visto! (1 episode 2014), Celebrity Home Raiders (unknown episodes 2014); as Self, completed: Fame Us (2016).
Edward Mulhare (Devon Miles): died in 1997.
Richard Basehart (Narrator - Opening Titles): died in 1984.
Patricia McPherson (Bonnie Barstow): last known acting role in 2009, then 1991 before that, as Self in 2011.
Rebecca Holden (April Curtis): in The Hand Job (2015); The Hollywouldn'ts (2016) in post-production; as Self, completed: Surge of Power: Revenge of the Sequel (nd).
Peter Parros ('RC3' Reginald Cornelius III): in The Haves and the Have Nots (83 episodes 2013-2017); as Self: The Tyler Perry Show (1 episode 2014).
Ann Turkel (Adrienne Margeaux/St. Clair, Bianca Morgan): last known acting role in 2006.
Catherine Hickland (Stephanie 'Stevie' Mason/March): last known acting role in 2012; as Self in 2013.
Lance LeGault (Vernon Gray, Christopher Stone): died in 2012.
Pamela Susan Shoop (Maggie, Marta Simmons): last known acting role in 1996, as Self in 2013.
Jack Starrett (various): died in 1989.
Alex Kubik (various): last known acting role in 2008 but Escort Service (2016) in pre-production.
Shawn Southwick (Lonnie, Rita Wilcox): in Christmas Eve (2015; also Producer); Lundon's Bridge and the Three Keys (2017) in pre-production; as Self: Home & Family (2 episodes 2015-2016), Extra (2 episodes 2016), WGN Morning News (1 episode 2016), Collectors Cafe (unknown episodes 2016), Entertainment Tonight (1 episode 2016).
Bruce Neckels (various): last known acting role in 2008.
Michael Masters (various): died in 2003.
* Brian Cutler (Bar Manager, Dobie): last known acting role in 2002, then this; as Producer in 2006, as Cinematographer in 2006.
* Phyllis Davis (Tanya Walker): died in 2013.
* Ramon Bieri (Al Farland, 'Acid' John Byrock): died in 2001.
* Anne Lockhart (Sherry Benson, Jennifer Shell): in Chicago Fire (60 episodes 2013-2015), Lockhart (2015), Avenge (2014), Dakota's Summer (2014), Parkland (2013), The Lying Game (2 episodes 2013); as Additional Voices: Wild Card (2015); as Loop Troup: Saving Mr. Banks (2013); as Self: Behind the Scenes of Dakota's Summer (2014).
* Judy Landers (Micki Bradburn, Sheila): last known acting role in 2011.
* John Considine (Boyd LaSalle, Phillip Nordstrom): last known acting role in 2005, as Self in 2007.
* James T. Callahan (Sheriff Bruckner, Jeff Barnes): died in 2007.
* Alan Oppenheimer (General Duncton, Joe Lewis): in Fallout 4 (2015 video game), Fall of Grayskull (2015), Adventure Time with Finn & Jake (1 episode 2014), Foxcatcher (2014); as Self: TV's Nastiest Villains (2014); as Self, completed: Toy Masters (nd).
* Joe La Due (Jack Kragen, Hannigan): last known acting role in 2003.
* John Crawford (Sheriff Moore, Mac Thomas): died in 2010.
* Don Galloway (Gilbert Cole, Harley Freeman): died in 2009.
* Guy Stockwell (Riggins, Zachary Sloate): died 2002.
* Mary Beth Evans (Cindy Mattheson, Nancy Marsden): in Days of Our Lives (535 episodes 1986-2016), The Bay (27 episodes 2014-2016, 39 as Producer), Chasing Life (7 episodes 2014-2015); as Associate Producer: Alec Mapa: Baby Daddy (2014); as Self: Serial Scoop Now (1 episode 2016), AfterBuzz TV's Spotlight On (1 episode 2016), The 83rd Annual Hollywood Christmas Parade (2014); as Self, pre-production: The 43rd Annual Daytime Emmy Awards (2016).
* Don Gordon (Police Lt. Dickerson, Randy Cavanaugh): last known acting role in 1993, as Self in 2005.
* Jason Evers (Herb Bremen, Edward Grant): died in 2005.
* Allen Williams (Major Sanderson, Jack): last known acting role in 2012 but Red Team Go (nd) in post-production.
* Noel Conlon (William Benjamin): in Hail, Caesar! (2016), North Blvd (2014).
* Robin Dearden (Liberty Cox, Mel): last known acting role in 2010 but Chicanery (nd), Fantasy Hospital (10 episodes 2016) completed.
* George Murdock (Judge Oliver Callan, Archibald): died in 2012.