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

Stan: Mom says to stop trying to give yourself cancer.
Randy: Just gonna get a little bit of cancer, Stan, tell mom it's okay.

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!

South Park Quotes

It's a man's obligation to stick his boneration in a woman's separation, this sort of penetration will increase the population of the younger generation.

</i> Cartman

James Cameron doesn't do what James Cameron does for James Cameron. James Cameron does what James Cameron does because James Cameron is James Cameron!

James Cameron