I heard this one on SNL…
“You know the more you talk, the less I want to have sex with you.”
Don’t get your balls in an uproar.
If you water it will it grow? 
i always liked “fuck you and the horse you rode in on!”
you slackjawed, flaplip piece of buzzard shit.
it is a wonder that you were not left for dead a long time ago.
YOU ARE THE REASON WHY NATURE ABHORS A VACUUM.
you do not have a family tree, yours is only a family weed.
what is it like for you when you crawl out from beneath your rock?
you have the attention span of a retarded golfish!
“You are a waste of skin.”
(To another person, but in the presence of the Annoying One:) “Do you hear a high-pitched whining sound?”
Ah…guess I just learned how to do a Smiley. Damn.
I love to lead in with the three words, “Important or Stupid”?
Which garners the inevitable “huh”?
And to which I reply, “Well you obviously haven’t been following the rules. Are you too Important to obey them or too stupid”.
Finally they realize they’re being insulted… 
My deepest sympathies to your parents. I know not too clever but it does make them stop and have to think.
My deepest sympathies to your parents. I know not too clever but it does make them stop and have to think.
Ain’t no plate tectonics. Just yo Mama.
and every bit as subtle. Scrofulous suppurating merhog. Beef witted chunk of pustulent detritus.
-I hope your earholes turn into arseholes and you shite all over your shoulders…
-Your mind must truly be a beautiful place - completely unspoiled by any knowledge whatsoever…
-If I want your opinion you’ll hear me say, “Hey fuckwit, what d’you think?..”
-You sniff little girl’s bicycle saddles…
-(to another male) I bet you wouldn’t even have the decency to give me a reach-around if you were fucking me up the arse…
“You debate like a creationist.”
Well, it seems quite a few people have the book “Shakespeare’s Insults.” I’ll have to post up my favorite as soon as I find it again.
I’m surprised that only one person has used Monty Python quotes. What about the Frenchman from ‘Monty Python and the Holy Grail’:
“Your mother was a hamster and your father smelled of elderberries!”
But my favorite insults are the wickedly subtle ones. I recently received the comment “You r a smeg head” in an email, so I responded with this (much longer than 25 words, but I love it):
“Smeg head huh? Is it just me, or have insults gotten progressively lame as of late? Try “cranially defficient troglodyte” or “unctious miscreant” for a change. And if you really want to hit the insultee hard, sounding superior is a must. Sadly, this just isn’t accomplished with abbreviations such as “r” (I’m glad to see, though, that you have enough class to spell correctly and avoid “u”). With enough practice, you’ll be able to evolve to intellectual levels envied by all your neighborhood internet junkies. Good luck and try hard!”
Ooh, that really hits below the belt. I now have a new favorite!
for a fat person - ‘fatso’
for a dumb person - ‘dummy’
for an elderly person - ‘old fart’
for a sick person - ‘sicko’
for an ugly person - ‘ugly’
for a smart person - ‘smarty pants’
for a clumsy person - ‘klutz’
for a slow person - ‘slowpoke’
for a girl - ‘girlface’
and my all around favorite - ‘jerk’
My most common insult- Evil demon bitch from all eternal hell
Said more out of silliness- damn you and all your damned damnedness
There really aren’t all that many insults I could use that other people would understand…
Kitty
Sir Dirx said of the insult, “You debate like a creationist,”:
Always happy to help!
Well, I’m a master of the Evil Death Stare, so when someone is bothering me I just stare them down with the Look Of Death. My friend Jay is excellent at insults, as is my friend Carlee, so I’ll check back in here as soon as I get a chance to talk to them.
Personally I’m fond of the aforementioned “mother was a hamster…” quote from Monty Python.
“Imbecilic son of a syphilitic prostitute!”
“I’d call you a jackass, but it’d be an insult to mules.”
“Your MOM!” *by itself or in context – eg person is bitching about pizza, YOUR MOM is a pizza, bitch!
person bitches extendendly; pause after they’re done “I’m sorry, what were you saying?”
I like to go to The Stand comedy club in Edinburgh and here are a few put downs that I loved.
1: Save your breath, you’ll need it to blow your girlfriend up when you get home.
2: Where did you learn to whisper? In a helicopter?
3: Oh I’m sorry. You seem to have misunderstood the concept of heckling. The idea is to make ME look like a cunt.
This is my favourite put down for someone who is getting on your nerves.
You ask them what they do for a living and then reply “oh yeh. I knew a guy who did that, but he made us promise not to tell his mother. She thought he played piano in a brothel”
Sharkboy
We’re gonna need a bigger boat!