Quote from song or book that'd make a good (clean) insult.

[Buttercup]

"Oh yeah? Well go put it in your pantry with your cupcakes!"

(I'm going to try that someday, really)

[Strange]

You are thick as a brick.

(Er, not you Buttercup!)

[Strange]

You have an atom heart, mother!

[Jens]

Not really an insult, but if I were a judge condemning someone, it would be nice to be able to say:

Bismillah no, I will not let you go!

[Romanus]

My best clean insults come from...well...an old book of clean insults.

One that I actually use: "He has risen from obscurity and is headed for oblivion."

[snowcelt]

I read a good insult somewhere which went something like "He thinks himself a wit; but, I think he is only half right."

[Strange]

"He is a very modest man, but then he has much to be modest about."
"He has a face completely unmarked by the ravages of intelligence."

And to get back to the OP: your jokes are as stale as the doughnut in granny's greenhouse.

[nosbig5]

You're as wide as the air-car that chased my Barchetta.

[publiusr]

I love Bill Mahers take on the most uninteresting man in the world (Mittens):

"Paint watches him dry." "When it can't sleep, Ambien takes him..."

One for Robot Chicken:
"If somebody had blastered Palpatine while he was wearing a hoodie, imagine all the trouble that would have saved." Groan...

[Chaos]

One from Lord of the Rings: "I donīt know half of you half as well as I would like, and I like less than half of you half as well as you deserve."

And another, from the first Mass Effect game: "I havenīt been shot in the head nearly often enough for that to sound like a good idea."

[Jens]

Probably used, but:

Why don't you all fade away?

[LaurelHS]

My self-esteem's not low enough to date you. (Garfunkel and Oates)

[Solfe]

He’s perfectly in tune
He’s perfectly in time
He’s a legend in his own mind

[darkhunter]

From various books by Louis L'Amour: I've forgotten more about [insert subject here] than you know.

[Jens]

From Laurie Anderson:

He was an ugly guy with an ugly face, an also-ran in the human race.

[Tensor]

From Mother Hicks

"I don't want to go live with her, she has a face like a foot."

[jamesabrown]

He wore a face that women looked at once.

[mike alexander]

All the fine Yiddish insults and curses, such as:

May all your teeth fall out except one, and that one have a toothache.

Your luck should be as bright as the new moon.

And the nastiest one I can think of:

A young child should be named after you.

[PetersCreek]

Weird Al Yankovic is known for his parody songs of course but this is from one of his originals, "Good Enough For Now:"

You're sort of everything I ever wanted,
You're not perfect, but I love you anyhow.
You're the woman that I've always dreamed of,
Well not really, but you're good enough for now.

[Strange]

"Frankly, my dear, I don't give a damn"

[Bobbar]

"Your mother was a hamster and your father smelt of elderberries."

[KaiYeves]

I'm partial to Josh Lyman's "You are a waste of the oxygen useful people could be breathing."

[grapes]

"these foetal-voiced people couldn't blow a sick maggot off a dead beetle"

I couldn't be remembering that wrong, could I?

[jrkeller]

You give love a bad name.

Rebel, rebel, your face is a mess

You Talk too Much - George Thorogood version

You're so vain

A pretty face don't mean a pretty heart

I hate myself for loving you

[Gemini]

A southern man don't need him around anyhow!

[headrush]

Is this a piece of your brain ?

(sorry not a song or a book but wickedly funny and useable)

[KaiYeves]

"Go stuff a cactus, Custer!"

[SkepticJ]

"You couldn't pour urine out of a boot, even if the directions were printed on the sole."

"You're a waste of skin."

"Only a virgin would be impressed."