What's the best insult you've ever heard?

[FllMtl Novelist]

Reminds me of a trick I used to play on every copy cat (CC) I met:
Me: "Stop copying me."
CC: "Stop copying me."
Me: "I'm stupid."
CC: "I'm stupid."
...
CC: "Hey!!"

This doesn't work on my siblings anymore. Once in a while they'd all start repeating each other just to be annoying, so of course this remedy was thought up. But now it doesn't work:

Me: Stop repeating me.
Sibling: Stop repeating me.
Me: I'm an idiot.
Sibling: You're right. You are.

Or

Sibling: At least you have the courage to admit it!

Or the simpler

Sibling: You're an idiot.

Sometimes the person being repeated knows this will happen, and assumes the other will just be contrary in repeating who the first person said is an idiot. [What a hairy sentence that I'm not sure I got right. XD] This results in exchanges like this:

Me: Stop repeating me.
Sibling: Stop repeating me.
Me: You're an idiot.
Sibling: I'm a--ha ha--you're an idiot.

[J.D3]

My older sister once said to me "Gosh, if you were any more mellow, you'd be dead!"

[Paul]

You sorry silly stupid sack of entrails! Vengence is mine!

[Rusty Claymore]

I prefer insulting myself, and my fav comes from Trigun Ep 1.
"I ain't got no kids and most women find me pretty offensive so I'm single."

And for the case of insulting someone else, "You need to die! It'd sure make us all a lot happier if you do." Rebuttled(if performed against you) by, "I'm sorry, I don't do requests."

[Winry]

You bob for apples in the toilet... and you like it!

[Shao Feng-Li]

I like Yo Mamma insults.

"Yo mama's so fat, the back of her neck looks like a pack of hot dogs."

And so on.

[Sheenar]

I like Yo Mamma insults.

"Yo mama's so fat, the back of her neck looks like a pack of hot dogs."

And so on.

http://www.youtube.com/watch?v=V4n0F9R90F0
(No cursing or inappropriate language that I can remember.)

[J.D3]

I prefer insulting myself, and my fav comes from Trigun Ep 1.
"I ain't got no kids and most women find me pretty offensive so I'm single."

And for the case of insulting someone else, "You need to die! It'd sure make us all a lot happier if you do." Rebuttled(if performed against you) by, "I'm sorry, I don't do requests."

I love that one in Trigun. Packs me up every time!

[Beau Soir]

Pingas

How mature...

[Nate]

Snooping as usual I see.

[Rusty Claymore]

Hoidy-toidy mister God-like smarty pants.

[Nightshade X]

"Your soul is an appalling dump heap, overflowing with the most disgraceful assortment of deplorable rubbish imaginable... mangled up in tangled-up knots!!"

[Tamachan319]

This is more of a loving insult,because my friends and I say it to each other sometimes as a joke.
"You're special---which is a euphemism for WEIRD."

[Nate]

I always knew it was really called "Weird Ed."