Randal "Randy" Marsh is Stan's father and as a geologist he's surprisingly involved in a lot of the plotlines in South Park.   Randy has also been revealed to have a decent singing voice, having been involved in a boy band as a kid, and knows how to play the guitar.

Randy Marsh Quotes

Randy: How does it feel to be a hundred and two, Paps?
Grandpa: Shoot me!
Sharon: Make a wish, Grandpa...
Grandpa: I wish I were dead!
Randy: That's our silly Grandpa!
Grandpa: I'm not kidding, God Dammit! I really want to die!

Randy Marsh: I think I'm getting that stomach flu you gave me.
Mr. Garrison: It's that little Kenny bastard that gave it to me.
(the mayor exits the porta-potty)
Randy: Hey, mayor. Were you making gravy in there?
Mayor: I just gave birth to a brown baby boy.

South Park Quotes

No no no, I'm telling you guys, music videos have devolved to nothing but pretty girls, wearing skintight clothes, singing about their vajayjay. Used to be chicks talking about relationships, now it's all my vajayjay this, my vajayjay that. But clearly that's what sells.

Cartman

Kyle: You can't die Mr Hankey, you can't.
Mr. Hankey: (Cough)
Kyle, before I go, there's something I must tell you. Come closer Closer
Kyle: What is it Mr Hankey?
Mr. Hankey: There is another Skywalker. Uhhh (Mr Hankey dies)
Kyle: Nooo
Mr. Hankey: (Mr Hankey appears to be alive) Wait Kyle.
Kyle: What is it Mr Hankey?
Mr. Hankey: Come closer
Kyle: What is it?
Mr. Hankey: Closer
Kyle: Yes?
Mr. Hankey: Closer! (Pause) One time, when you were sleeping, I put myself in your mouth and had my friend take a picture. Uhhh (Mr Hankey dies)
Kyle: Nooo