I had a character who was basically sidhe (I won't bore you with the details). He had to tell the truth, had to keep his word, was scarred by iron etc. Off the top of my head I recall one incident where he was in a real estate office, trying to distract the realtor while his allies investigated the back of the office. I started by saying that I was in the market to buy a building, etc., but then the GM tossed a compel against my high concept at me: I wasn't actually looking for a building to buy, I was really there as a distraction, and my character couldn't lie.
Chagrined, I thought for a moment, then told the realtor something to the effect of "I have a lot of money available right now (true, my character had 4 resources and the Lush Lifestyle stunt) and my current office space is a little small for my expanding business (also true, though my character didn't care enough to look for a larger one; he liked his current arrangement), do you have any attractive building spaces listed that might suit my needs?"
In this way I didn't tell an untruth, but I left the impression that I was looking to buy without ever coming out and saying so.
Another time I gave my word to an old acquaintance that I would do whatever it took to save her granddaughter's life. Later on we got in a huge fight, and the granddaughter was on her back two zones away, surrounded by ghosts and cultists. Normally my character stuck to the back, sniping, but my GM tossed another compel at me. I needed to fulfill my word, and right now the girl was in danger. With a sigh, I broke away from the rest of my group and struck out alone into the center of the fight, and managed to save her life, though not before more complications ensued and were dealt with.
I also occasionally got compels for avoiding iron and such. Being sidhe introduces complications, but assuming the character knows what they are in for, they are the good kind that add excitement and make good memories.