I think the following words are sadly underused, and would be delighted to see more people employing them in polite conversation:

WHOREMONGER: as seen scrawled on a piece of paper on a cuckoo-for-Jesus-puffs manifesto stuck to the bus stop this morning. Apparently, if you mong whores, you are going to Hell. I guess I'm okay to do it though since I've already, apparently, licked the devil's labia. Sheesh.

WHOREMASTER is also acceptable.

FUNDAMENT: Not actually one of my favorites, but I could always use another word for butt.

GALUMPH: What? It's a word. Honest.

DETRITUS: I once kissed a man just for using this word. Okay, so I was drunk. But I am very fond of it. It can be used to delicately express what would otherwise be considered...distasteful. For example, instead of Paris Hilton has a lot of petrified jizz in her rancid, foul hole, you can say, Ms. Hilton has a great accumulation of detritus (or offal, debris) in her vagina.

FLANGE: As seen on the box of ass gaskets provided "courtesy of the management" in a public restroom near you (instuctions: push toward wall and let down BEHIND the guard flanges).

Now use them all in a sentence for fun and profit!
Well, fun, anyway.

For example, The whoremonger galumphed over to her screaming that she was the detritus of Los Angeles, and commanded, "shut your flange!" before whacking her in the fundament.

Now you...! What are your favorite words?