In terms of insults on film/tv I appreciate a lot of Armando Ianucci's writing which finds its way in The Thick of It/Veep/Death of Stalin, etc

"You're not even a man. You're like an early draft of a man, where they just sketched out a giant, mangled skeleton but they didn't have time to add details like pigment, or self respect. You're Frankenstein's monster, if the monster was made entirely of dead dicks."

"He's so dense that light bends around him"

"You sentient enema"

"How would you like to suck my balls?"

- Eric Cartman.

 I must say with my entire heart this has to be one of mine as well. Cartman is a historical figure in the insult community.  

Complementary shoutout to Stan

Stan: If my mom could cook like Cartman's mom I'd be a big fat ass, too!

There's the classic which was attributed to Winston Churchill, he was at some event and a lady attending the event said "Sir, you are drunk", his reply was "Madam I may be drink, but you are ugly, and in the morning I'll be sober".

I find with insults, less is more. Nothing is as insulting as being called a "cunt".

With a sufficient array of adjectives, it's a very versatile insult too. Smelly, ignorant, loathesome, repulsive, arrogant, rude, dumb... they all work. It's the ultimate insult, and if you stick it after "good" or "smart", then it can even be turned into a compliment. Cunt - it's the Swiss Army Knife of insults.

If I wanted lip, I'd tell your mother to drop her panties.

"Okay, Flaming Dragon. Fuckface. First, take a big step back... and literally FUCK YOUR OWN FACE! Now, I don't know what kind of pan-Pacific bullshit power play you're trying to pull here, but Asia, Jack, is my territory. So whatever you're thinking, you'd better think again. Otherwise I'm gonna have to head down there and I will rain down an ungodly fucking firestorm upon you! You're gonna have to call the fucking United Nations and get a fucking binding resolution to keep me from fucking destroying you. I am talking scorched earth, motherfucker! I will massacre you! I WILL FUCK YOU UP!" 

-Les Grossman, 'Tropic Thunder'

One of my favorite monologues of all time.

Bitch ones.

If you don’t like me but still watch what I do – Bitch you’re a fan.

Twinkle Twinkle Little Snitch Mind Your business nosey bitch.