Yeah, okay.

A sarcastic remark used when one is doubtful of someone else's claim.

Person 1: Dude, I totally got laid last night.
Person 2: Yeah, okay.

yeah boy

Flava Flav's Public Enemy catchphrase. It usually starts the shit, with Termanator X and Chuck D bringing it afterwards. However, anyone can say it, as long as you mean it. It is one of the most positive things you can say. It's the best.

Chuck D- Somebody in the house say yeah. If you really like to rock the funky beats, somebody in the house say HELL YEAH.
Flava Flav- YEEEEEEEEEEEEEEEEAH BOYYYYYYYY

or

Friend- You want to go get some tacos and tequila?
You- YEAH BOY

yeah son!

Term coined by the notorious DJ Avery. Can be used in any situation, usually to convey approval. Emphasis on the "Son" is key.

Person 1: "So whats the deal, you headin' down to Dubbage tonight?"

Person 2: "Yeah son!!"

yeah yah

to express joy in something charming and apparent.

"another episode of strangers with candy, yeah yah!"

Hell Yeah

Derived from "In the name of hell, Yes!", this saying expresses either great joy or agreement with either a speaker or an ongoing situation. It has been made popular by the WWE's (Formerly WWF) "Stone Cold" Steve Austin.

"If you want to see Stone Cold open a can of whoop ass, gimme a Hell Yeah!"
Response: Hell Yeah!

yeah-huh

An affirmative comeback, commonly used after "nuh-uh."

A: "Did you see that Amy got a nose job?"
B: "Nuh-uh."
A: "Yeah-huh."
B: "That crazy bitch."

fosho yeah

An abbreviated way to say yes with enthusiasm, this exclamation is the next level up from fo sho.

M: Did you get your longboard yet?
B: FOSHO YEAH! It just arrived yesterday. It's so sweet dude.