My, this is a big internet topic!
Here's a list. I'm seeing some repeats from the inherently funny words discussion (e.g., succotash).
Here's an even longer list. "Obfuscate." Man, I say that in class all the time (when talking about the Supreme Court).
And here's a list of 94, with voting on which sounds dirtiest. #1: "ballcock."
Then there's the song (which I guess is actually NSFW):