Hapless... funny how you can't say 'hapful' or use simply 'hap'... isn't the English language great. But seriously, I enjoy the image this word conjures up; it just seems so distressed.
Facetious... Physics Boy uses this one all the time and it just sounds so much more sophisticated than plain old 'sarcastic' or 'joking'.
Mishap... because saying "I had a slight mishap with the floor' sounds much better than "I tripped and fell on my face."
Splendour... so elegant, and because I say 'beauty' far too often. (I am very enthusiastic about everything)
Comely... much more sophisticated than 'OMG HE'S SO HOT!' (Speaking of, there were three attractive boys plus a man who looked like Rory from Doctor Who crossed with Nick from New Girl sighted at work today... and yet none of them went through my cash. Just my luck.)
Desultory... because it sounds better than 'lazy'... If I use this one, people might think I'm actually busy!
Defenestrate... just because it sounds slightly kinky. (But really only means 'to throw out a window'.)
As you can see, my main goal here is to dissemble (another wonderful word) about my life and make myself seem like less of an idiot. (Hey, at least I'm being honest!) Are there any words you'd like to use more? Or that you use every day?