How many episode titles do you know of that were dropped in dialogue?
Two that I know of are from Hart to Hart near the end of its first season: one is from “Cruise at Your Own Risk,” 4/8/80:
Stanley: “Remember the burglary on the sister ship Josephine about a year ago?”
Jonathan: “Yes.”
Stanley: “And you didn’t want a heavy insurance investigation?”
Jonathan: “Well, I thought it would be like hanging out a sign: cruise at your own risk.”
Another is from the penultimate outing, “Too Many Cooks Are Murder,” 5/6/80:
Frank: “You’re not carrying anything. Where is it?”
Pierre: “The Harts came in before I could search.”
Frank: “I sincerely hope Maurice doesn’t deal with Hart.”
Pierre: “He won’t be dealing with anyone.”
Frank: “I see. Well, we must take care that our good friend Jonathan doesn’t find it before we do.”
Pierre: “I took care of Maurice. I can take care of Hart too.”
Frank: “Yes, that’s right. Too many cooks are murder.”
All good ones! IIRC, in episode 4 of Hart to Hart, Oct. 6, 1979, the child introduced himself as Jonathan Hart, Jr., which of course was the name of the episode.
MISSION: IMPOSSIBLE was thick with this, due to sheer damn plainspoken laziness. They did an episode called “Charity,” where swindlers run a phony charity. They did an episode called “Casino,” where the mob runs a casino. Plus they did an episode called “Orpheus,” where the guy’s codename is Orpheus; they also did an episode called “Elena,” where the girl’s real name is Elena; and they did an episode called “Chico,” with a trained dog named Chico.
They did an episode called “Blind”. They did an episode called “Cocaine”. They left a movie camera running on a movie studio to frame a moviemaker for murder, and called the episode “Movie”. We’re going to be here a while.
IIRC, on The Man from UNCLE, they not only included the episode title in each episode, but they had “quarter titles” for each section, and they all showed up as dialogue. The shows were fairly campy in tone.
This happened pretty often with Stargate SG-1, largely because the episode titles were generally kept simple and relevant. For example, an episode with a plot-critical alien artifact referred to as “Thor’s Hammer” was entitled “Thor’s Hammer”, so the name was used repeatedly throughout the episode (and referenced in later episodes). Similarly, the episode title “1969” referred to the year of the events in the episode, so any reference to the date was also a title drop.
Closer to the OP’s aim, I think, would be “The Fifth Race”. It’s not a common phrase, and isn’t said until near the end. Until then, there are only mentions of four races who were members of an ancient alliance.
Finally, there’s the special case of the episode “Wormhole X-Treme”, where the title of the episode is the title of a show within a show that is a parody of the show itself.
I believe this is common on reality shows as well; I think most (if not all) Survivor episode titles are quotes from the players.
Arrested Development did this with the name of the show at one point, and the narrator (Ron Howard) actually calls it out, “Hey! That’s the name of the show!”
Game of Thrones does this often, from its first episode, “Winter is Coming” to its most recent, “Mhysa”, perhaps most memorably with S1 Ep7 where Cersei snaps off both the episode and series title “You Win or You Die” when confronting Ned Stark. (“When you play this game of thrones, you win or you die.”)
I think it happens a lot in Game of Thrones. I’m pretty sure the phrases “Valar Morghulis” and “Valar Dohaeris” were uttered in those episodes. “Kissed by the Fire” was said by Ygritte in that episode but I am sure meant to reference other things. “What is Dead May Never Die” and “Now His Watch Is Ended”, I’m sure were said in those episodes and in the episodes titled after songs, “The Rains of Castamere” and “The Bear and the Maiden Fair”, I think at least used those songs somewhere in the episode. And those are the only ones I can remember right now.