Two more I’ve heard over the years:

‘You should carry around a potted plant to replace the oxygen you’re wasting’

And:

‘Your head is really just a place to store your teeth isn’t it?

The Monty Python French taunters classic is a scathing insult and noone gets it. Break down the line:

"Your mother was a hampster, and your father smelt of elderberries"

Firstly, they are calling your mother a fast-breeding rodent, ergo, your mother is a whore, that one is simple. Second, why would your father smell of elderberries? What was it used for at the time? Wine, but better wine would be made from grapes from France or southern England, implying your father was was not just a drunk, but a cheap drunk.

Its one of the most insulting lines ever uttered on film and it has so many layers, which is why that movie is hillarious.

"Anyone ever tell you that you've done a great job lately?"

"No" (This one requires a no answer)

"Think about that, then."

I've always been partial to:

"You're at the top of the bell curve!"

Because it sounds like a compliment, gets taken as an insult, but really you're just calling them average.

It's a whole different level of demoralizing when they finally figure it out.

One I saw on Lemmy and remembered was "You have nothing but potential"

A few I've acquired over the years.

• "At this point, you can only impress me."
• "My opinion of you can only go up from here"
• "The bar was on the ground and you brought a shovel."
• Unencumbered by the thought process.
• "You're the reason we have warning labels."
• "They only got two brain cells and both of them are fighting for third place."
• "It's impossible to underestimate you."
• "If you were half as smart as you think you are, you’d be twice as smart as you really are."
• "If you ever had a clever thought, it died alone and afraid."
• "They never open their mouths without subtracting from the sum of human knowledge."
• "He can compress the most words into the smallest idea of any man I know." - Abraham Lincoln
• "May I ask what's on your mind, if you'll forgive the overstatement?"
• "You could hide your own Easter eggs."
• "I can explain it again, if you'd like, but I can't understand for you."
• "He is a modest man with much to be modest about."
• "I would agree with you but then we would both be wrong"

The classic:

• You look easy to draw

Others:

• You are the type of person who makes the teenage cashier at Chipotle explain why guac costs extra.

• You're the human equivalent of a bag of salad that goes bad the day you buy it, worthless after I already spent my cash.

• Talking to you is like using a public restroom, sometimes necessary, never pleasant and leaves me feeling a little gross after.

• Every conversation with you has the emotional texture of a Terms and Conditions pop-up.

• Being around you feels like watching someone try parallel park for four minutes.

and the best I have ever hear with my own ears, which is not mundane, but is excellent when yelling at the top of your lungs so all the neighbors can hear: "You are a supercilious cunt"

“The other sperm just let you win, didn’t they?”

"[W]hat you've just said is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul."

You have a great face for radio.

I'd try to explain it slower but I don't believe speed is the problem

"If all the village idiots, in all of the villages, left their villages, and formed their own village, of idiots. In that village, you would be the village idiot." - Colin Lane

"Don't be so humble. You're not that great." - Maria Bamford's dad.

"People say you're a real wit, but I think they're only half right." - me

I enjoy how you always find a way to renew my appreciation for silence.

i like curses more like: "i hope you stub your toes", "have a warm pillow", "may the consequences of your actions be harsh" or "may your phone screen be always too bright or dim"

For two people who look/are dressed similarly: "you look like the before and after photos for a product that doesn't work."

Not sure if this qualifies but I always liked the countryness of "so stupid they couldn't pour piss out of a boot if the instructions were written on the heel".

I was playing TF2 the other day and someone senta message in chat that was just a link to a state unemployement benefits page lmao.

I saw this on here recently:

"Working with you is like losing two good men"

"Eat any good books lately?"
..my favorite way of calling someone stupid

My absolute favorite...

You're not pretty enough to be that dumb

One I remember reading a while ago "your boyfriend looks like he drops common loot when he dies"

Two I like from history:

A lady called Winston Churchill drunk. Churchill replied: "Madam, I may be drunk, but you are ugly. I shall be sober in the morning."

Robert Muldoon, Prime Minister of New Zealand, when asked about the migration of NZers to Australia replied "Well, it raises the IQ of both countries."

Sittin' outside of a Wendy's for free wifi lookin'-ass

"Who's this clown?"

I'm fond of it for two reasons: calls them a clown and implies that they aren't even a memorable one.

ITT: A bunch of exotic insults that make people look like redditors

"A face for radio" is a classic

"This is why people talk about you"

You're not loved, they just tolerate you.

"The young gentleman is an excellent ration powered space heater."

Heard this back in basic for a young officer cadet who was absolutely useless aside from the fact that they were capable of heating up a ten person tent via their normal body heat.

You look the way I feel.

Heard a new one related to men dating women way too young for them: "Those old men walkin' around with embryos"

From a goodwill cashier

The comments have devolved into the less mundane and just regular insults, so I'll throw this one in here:

You're as thick as a brick sandwich

Don’t argue with that guy, he’s the Joe Rogan kind of smart.

Until hearing you talk, I never thought lobotomies could make people smarter

‘Daft bint’

I wish that for just one time you could stand inside my shoes

And just for that one moment I could be you

Yes, I wish that for just one time you could stand inside my shoes

You'd know what a drag it is to see you

Bob Dylan, Positively 4th Street

It's really hard to overestimate you.

To a performer: “Every time you perform is better than the next.”

To anyone: “I find you argumentative and easily offended.”

Best part of an insult is heading off the retort.

I'd rather shit in my hands and clap

my brother like spanish but did not know enough swear words so he would say things like fume mi huevos.

I hope your chooks turn into emus, and kick your dunny down.

Couldn't happen to a better person.

(After a trajedy or mishap)

"I feel like those shoes belong to someone with a better bowking average."

Assassin of joy.

"You're not as dumb as you look," was always one of the most subtle yet broad insults.

You're the enemy of fun.