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!
by TimmyT-SF November 28, 2023
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When a stupid guy/girl doesn't know anything about football
Isaac-"CR7 is the GOAT of football"
Smart guy-"This boy doesn't know shit about football mate"
by Abdi Carlos April 12, 2018
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do the streets know

Is this information known to the public
Hey man do the streets know you and Jenny are fucking” “ nah man, don’t tell no one”
by Didi27 January 23, 2023
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Timothy C Knows

A cool person who is pro at Speech and Debate, and it can't be denied that he is better than the undeniably annoying Gina. As you can see, he is a pro at oratory and congress. He rules the Whiz Quiz world, and he is a man of all people. I've never seen any skilled person know his maps and schools so well. This guy knows himself very well, and he can roast you pretty well, as he can find a way to beat your arguments 99% of the time. It's crazy how people underestimate him, but he knows his skills, as he can be your GPS anywhere. Plus, this guy knows schedules and dates so much that he will beg you to answer him, or else you will be damaged. He also loves sports and really likes Luka Doncic cause he's super skilled, and his basketball IQ is extremely high. It's almost crazy how he's good at so many things, and he is very competitive, so don't expect to beat him. His Instagram is the power machine of followers, and he knows his Instagram style.
Hey, it's Timothy C Knows.
Congratulations, you're so good, Timothy C Knows.
That guy, Timothy C Knows, literally beat us by a whopping 37 points.
Nice to meet you, is this TImothy C Knows?
by TheManHasSkills October 19, 2020
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The All Knowing Bug

The All Knowing Bug knows all and everything he says is right he will never say anything wrong.
The All Knowing Bug knows what you did.
by The All-knowing Bug. May 24, 2022
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