Some words really sum up their subject matter better than others.
Chunky. It just sounds big.
Cunt. And I mean in the insulting fashion here, this word is one of the best expletives around.
Beige. No other word – or colour – gets boredom across quite so vividly.
Cynical Optimism 
I have one, it’s one I can’t stand:
Moist.
Doesn’t that just sound icky and ..wet?
I know a few people who don’t like that word. Strange, but yeah.
And the age-old question: why is “abbreviation” such a long word? And “big” so short?
Why does ‘lisp’ have an ‘s’ in it? :p
Lisp reminds me of Countdown, being it the programme that introduced me to that funny fact of it containing an S.
I always quite liked vehement.
Ooh. Vehement is cool.
I also like ‘rage’. It’s so angry-sounding.
And tentacles. Haha.
Tentacles makes me think of a friend. And a certain DVD.
I quite like quiver, and wibble. Not sure why wibble.
Two good words that I want to get into a conversation at some point:
pleonasm: the use of more words than are necessary to express an idea.
nescience: lack of knowledge or awareness.
Nescience is nice. Prescience is just as good, but probably more popularly known.
I like ‘self-righteous’, too. It has a grind to it.
Aye – it’s nicely negative!
Speaking of which, “nice” may the the most horrible word in the English language. It’s so drab… so beige, in fact.
Oh really? That’s nice.
Almost like “fine”.