eh, I'm rather fond of 'sesquipedalian'. It's so cool that spell check won't even recognize it as a word. It means 'having many syllables' or 'someone fond of using overly large words', and it's ironic because it is a sesquipedalian word itself, and if you use it then you are one as well.
My second favorite would have to be ungulate, which means 'hoofed mammal'. I don't know why I like it, but it just strikes my fancy.
When it comes to length I keep antidisestablishmentarianism in my mind. Not as cool as the pneumono.. erm.. lung disease caused by volcanic dust, but it's non-technical.
Flibbertigibbets! I think I confused 2 people in one page just by saying that while rambling. It's quite effective, especially if you make it sound like you're talking to yourself or insulting a guy in a satirical fashion.
I've actually always disliked antidisestablishmentarianism as a word. While it isn't exactly a double negative because the anti- and the dis- are not both directed at the same concept, it just never sounded right to me.
there are so many negatives that most people have trouble figuring it out.
That's because most people don't know what Establishmentarianism is, or they simply don't care, as it is applied primarily to either politics or religion.
Idiot, fool, helpless, Shweinhund (not sure of the spelling), pathetic and child are all great mean words if used right. My favorite word is troglodyte.