We just finished watching the whole run of Barney Miller. In a rarity, there’s a scene set outside the squad room when Barney gets thrown in jail for not naming an informant.
His cellmate: William Windom. Recognized him by voice alone as he wasn’t shown. Played a grumpy guy, of course.
In an aside, there have been some other interesting guest stars on both St Elsewhere and Hill Street Blues lately:
Michael “Cosmo Kramer” Richards as an investigative journalist on SE.
Louise “Mary Hartman” Lasser as “Victor Ehrlich’s ditzy aunt Charise” on SE.
Meg Tilly (“Chloe” in The Big Chill) as a hooker in HSB. She would later have another role in the series, in which she gets whacked by The Mob.
John “Cliff Cleven” Ratzenberger as a fake cop/shakedown artist on HSB.
Eric Laneuville, “likeable orderly (and later EMR) Luther Hawkins” on SE, as a stone-cold killer on HSB. I’ve seldom seen an actor play two such different roles so convincingly.
Gail “Alixus” Strickland as “Gail Kennedy” in the Hill Street Blues episode “Invasion of the Third World Body Snatchers.”
One of the best exchanges ever comes in this episode:
Leo Schnitz: [Talking about Officer Renko’s deceased father, whose body has been stolen] You really think he could be sold for parts?
**
Lt. Howard Hunter:** Oh, well, corneas alone are going for upwards of seventy dollars a gram, Schnitz.
Det. Henry Goldblume: Howard, the man’s body was riddled with cancer!
Lt. Howard Hunter: Oh. [Pause, then] Well, there’s always the Third World markets.
I love Howard! 
Just saw the 1962 Cold War paranoia thriller The Manchurian Candidate, which doesn’t hold up all that well, but features several familiar ST:TOS faces:
Whit Bissell (scroll down to 1962)
Whit Bissel, Commissioner Lurry in The Trouble With Tribbles, i*n Have Gun Will Travel *as a bad guy, “Fairchild, Wife Killer” in The Burning Tree.
Played of course, by James B. Sikking, Captain Styles from Star Trek III: The Search For Spock, and later, Doogie Howser’s father.
Just saw quite a few ST actors in One Flew Over the Cuckoo’s Nest:
Jack Nicholson, alas, was never in any version of ST.
Deforest Kelley in Have Gun Will Travel, not written by Gene Roddenberry, *The Treasure.
*
Lycia Naff, aka “Ensign Sonya Gomez” in TNG, as “Maddy” in the St Elsewhere episode “Saving Face.”
FUN FACT: Naff also appeared briefly in Total Recall as the three-breasted mutant on Mars. 
A pre-TOS lineup of ***ST ***actors in one production: Felix “Mr Johnson” Locher, Majel “Nurse Chapel” Barrett, Shirley “Ruth” Bonne, and Nichelle “Lt Uhura” Nichols, in the Ann-Margret vehicle Made in Paris (released February 1966).
Just saw an uncredited William Schallert (Nilz Baris from ST:TOS “The Trouble with Tribbles”) as an Army Air Corps pilot on Guadalcanal in the 1960 James Cagney movie The Gallant Hours.
Cool!
Robert Easton, the “Klingon Judge” in ST VI: The Undiscovered Country, as a “Yokel” in “The Ransom of Red Chief” segment of O Henry’s Full House (1952).
Tim “Tuvak” Russ and Mickey “Kloog” Morton in the Hill Street Blues episode “The Virgin and the Turkey.”
Gina “Manua Apgar” Hecht on TNG as “Allison/Bonko” in the ***St Elsewhere ***episode “Tears of a Clown.”
Alfre Woodard (“Lily” in First Contact) and Michael Horton (multiple roles in Voyager, First Contact, and Insurrection) in the Hill Street Blues episode “Praise Dilaudid.”
Was scrolling through this entire thread as part of my post-Christmas procrastination before getting on with work, and this item caught my eye.
Don’t think it was mentioned that Kelley and Whitney were in Roddenberry’s pre-TOS pilot Police Story, a CSI-type procedural that wasn’t picked up as a series. (Too far ahead of its time, I guess.* 
)
I’ve never seen this show, but I’ve read a little about it. I wonder if there isn’t a video of it somewhere out there.
*Roddenberry would later collaborate with one ***ST ***writer (Stephen Kandel, maybe) on another such project, The Centurions, which (sadly) wasn’t picked up either.
Don’t think it’s been mentioned that Chad Allen (“Tommy Westphall” on St Elsewhere) was “Jono” in TNG’s “Suddenly Human.”
This is my best one. Leonard Nimoy in the* Highway Patrol *episode,Hot Dust, 1957.
Nimoy is a “kid” moving radioactive material, drops it off a scaffold, and is exposed to it. I haven’t seen all the episode, but I doubt that nictitating membranes will save him.
Well, heck, he didn’t die. I was hoping someone would say, “He’s dead already.”
dammit.
Wow - I never made the connection. Good one!