Well, I think something like this was like the first thing I posted here ever, or something like that.
But I figured I'd test the waters again, because I know my favorite word has changed.
I forget what I said before, but now I have 3 candidates.
1. Machiavellian, because it's hard and fun to say.
2. Unsavory, because it can be used in so many beautiful ways. "How do you like my dress? I find it, uhhh, unsavory"