“What do you want, you moon-faced assassin of joy?” Londo Mollari, Babylon 5
That 70’s Show: “Dillhole”, or worse yet, the dreaded “Double Dillhole”.
My favourite is “about as sharp as a sack of wet mice”.
Which was a sanitized version of the line from Gabriel Kaplan’s stand-up routine about his own high school days (which inspired the Kotter series): “Up your hole with a mello-roll!”
Hello, Newman.
Huh huh…shut up, Dillweed, huh huh.
Stifle it, Meathead!
MST3K liked to call someone a “Dickweed.”
The cops on The Chicago Code liked using the term “Jag Hole.”
I thought both had nice rings to them.
Minor nitpick: Those old Warner Brothers cartoons were actually made for movie theaters, not TV. So these are really “movie insults”.
Baldrick, you wouldn’t see a subtle plan if it painted itself purple and danced naked on top of a harpsichord, singing “Subtle plans are here again!”
Every episode of Deadwood.
“hooplehead”
“God’ll get you for that, Walter!”
“Dingbat!”
“I hate spunk!”
Chef Gordon Ramsay:
“You bleep! Bleeping bleep!”
When he’s not quite so unhappy:
“You donkey!”
Ren, to Stimpy:
“You EEEdiot!!!”
Jane, you ignorant slut.
One of the classics! 
I wonder how many of those originated with Senator Claghorn?
We could always watch and find out. It’s pretty long; I never bothered with viewing more than a few short clips.
And I know they were in movie theaters originally, but not in my lifetime. 
Dr. Smith to Robot: “Bubble-headed booby!” “Pusillanimous pipsqueak!”
LOL! Thanks for that little stroll down memory lane!