I don’t think I’ve ever seen a full episode of Leave it to Beaver, but the name Lumpy Rutherford lives in my brain for some reason.
Abbie Normal, from Young Frankenstein, is another.
I don’t think the Airplane! cockpit trio, Roger, Victor, and Captain Oveur, have been mentioned yet. Of course their names are not so much funny in themselves, as funny in the context.
Trivia Challenge: What was Lumpy’s real name? 
Knobbly?
Nah, I know what it is but only because I confirmed that “Lumpy Rutherford” was an actual character name [by searching] before I posted. But others may enjoy demonstrating their knowledge!
Holly Golightly
Trivia Challenge Ii: Who played Lumpy’s father, and from what other popular sitcom of the 1960s is he known?
(He never referred to his son as “Lumpy,” BTW.)
Pacific Rim had some great names:
Stacker Pentecost
Hercules Hansen
Hannibal Chau
Chin Ho Kelly (Yes, he had an Irish surname.)
Kam Fong
Wo Fat
Konokapu Kalākaua, aka “Kono” (His full name was shown at least once on a business card.)
“Danno”
As long as we’re doing this again, I’ll also mention two of my fave characters from “Bored of the Rings”.
Truly Scrumptious should have been a stripper name.
Hard to say Abby Normal was a character, tho. Certainly not a fully fleshed out one, at least.
Lumpy Rutherford’s real name was Clarence. Mr Rutherford was played by Richard Deacon, aka Mel Cooley from the Dick van Dyke Show.
From The Usual Suspects:
Keyser Söze. Great villain.
Well done! 
Third mention.
My favorite name of a '70s porn star is Clitoris Leachman.
Sadly, I’m prohibited from posting my favorite name of a Monty Python character, so I’ll just refer to her as “She who exploded, as people do every day.”
For some reason, I had the name Eccentrica Gallumbits (from one of the Hitchhiker’s Guide books) stuck in my head all weekend.
Given that the novel on which the movie was based was written by Ian Fleming, it would also have been a great name for a Bond Girl.
Did anyone mention “Bolt Upright” from the Beverly Hillbillies?
Can’t forget “Miles Long” 
I just put a copy of that book in my library bookstore today! I found the concept amusing, too.
James Michener’s “Space” had a fake TV preacher (is there any other kind, really?) who dubbed himself Dr. Leopold Strabismus. It also had a fictitious 51st U.S. state called Fremont.
How about “Dash Riprock”?