Star Trek was a show on a mission, but that plan didn't necessarily account for the ship's doctor, Leonard "Bones" McCoy, who earned more and more of the spotlight at the series progressed. But that's what happened as Bones became a fan favorite and factored more heavily into plots. This gave the actor who played Bones, DeForest Kelley, ample opportunity to repeat lines that became some of Star Trek's most memorable catchphrases.

When you think of Bones, which catchphrase comes to mind first? Do you immediately proclaim with a fierce integrity, "I'm a doctor, not a _________"? That's a classic.

Or, do you instead stoop to take an imaginary pulse before somberly declaring, "He's dead, Jim."

If it's the latter, you should be aware that you're perpetuating a catchphrase that started slightly irking Kelley the more often he had to say the line.

According to Mark Clark's Star Trek FAQ: Everything Left to Know About the First Voyages of the Starship Enterprise, Bones says "He's dead, Jim" approximately 20 times, occasionally varying the line to say instead "The man is dead!" 

As a ship's doctor in a Starfleet filled with Redshirts, it's not surprising Bones would be confronted with confirming these demises again and again, but that doesn't mean Kelley had to like it, and Clark notes in his book that the actor actually drew a line in the sand when they asked him to deliver the line following the death of Spock in Star Trek II: The Wrath of Khan. Instead, the writers passed the line to James Doohan, who said it just as somberly as Scotty.

From that point on, Kelley was free of the catchphrase, and after that, he was able to joke again about his often-repeated line. As for the other catchphrase, rest assured the doctor had no qualms with saying, "I'm a doctor, not a _________." He even once parodied the catchphrase on an episode of Rowan & Martin's Laugh-In, in a scene that had Kelley twisting the line to say, "I'm not a doctor, I'm a convicted murderer."

This catchphrase, too, spread beyond just Bones, becoming a go-to line delivered by characters in Star Trek: Deep Space Nine, Voyager and Enterprise. And of course, the recent movie remakes were sure to have Bones repeat the phrase for Star Trek's newest audience.

What's your favorite Star Trek catchphrase from The Original Series?