I know! Right?!

It's pretty clear what the speaker is trying to convey: "I agree."

I agree with most of the other definitions, which provide details on the subtle context/audience-dependent connotations. I agree that phrase is annoying, used by speakers who use other annoying phrases like "my bad."

I would like to add to what has been said by providing side-by-side analogs; that is, alternative, equivalent but more acceptable expressions.

Example Expressions

I can't handle this idiot any more!
I know! Right?! OR Damn straight!

In wish I brought my swimsuit.
I know! Right?! OR You're telling me!

I like this 'double it for a buck' happy hour!
I know! Right?! OR You can say that again!

I was gunning for Miss Tipsy, but I just got shut down by her fat roommate!
I know! Right?! OR Join the club!

This is good sauce.
I know! Right?! OR Yes, it is.

Let's not go to the Bubble Club. It's so damn expensive!
I know! Right?! OR You got THAT right!

I have an idea: let's strip and go wallow in the mud puddles.
I know! Right?! OR You're preaching to the choir!

Our corporate holiday event was so cheap it was insulting.
I know! Right?! OR I couldn't agree more.

They are good at talking all sexy.
I know! Right?! OR Mmm hmm!!

This is the correct line for us.
I know! Right?! OR Right you are.

Tacos.
I know! Right?! OR Yeee-ah boooooooyeeee!!

We're in trouble NOW.
I know! Right?! OR No shit.

Tonight, we wear The Boots!
I know! Right?! OR Fuckin A right!

I Prevail

An absolute garbage Metalcore band that sounds exactly the same like every other modern Metalcore band that is unfortunately enjoyed by Metalcore Kids. Listen to real bands like Earth Crisis, Hatebreed or Converge. Oh and by the way, they are also blatantly copying Soilwork's hard work of music.

Metalcore Kid: I Prevail are the best Metalcore band ever!

Me: ...

i hate them all

hating them ALL

Oh god its one of them. I hate them all.

I don't miss

Lincoln Stoner

Lincoln "I don't miss"

I Broke His Balls In The Sewage Town

Absolutely roughing up a crocker in his shimmy windle

Usually takes place between midnight and 1:06AM

Bro 1: dude did you fight that kid last night?

Bro 2: yeah man I Broke His Balls In The Sewage Town

I need to feed my geese

Humorous term for stating dat you hafta pause a moment to use your handkerchief, and thus you'll be making one or more loud "honking" noises. Generally said more frequently during da chillier months.

Saying, "I need to feed my geese" can indeed be a light-hearted way of informing your present company dat your nasal passages need clearing, but an even more delightfully-silly phrase to use might be, "I need to honk my air-horns"; said latter statement is also a more "obvious" way of saying it, since it more-closely resembles what you're needing to do.

i love amar

i love my beautiful girlfriend amar and shes shes so amazing and literally the BEST girlfriend/ best friend in the world if you think youre lucky, youre not because im even luckier and im with the love of my life!!

amars smile is so cute. thats one reason why i love amar