Apart from supermarket car parks, I hate using airport car parks. You can park in what looks like a fairly low risk space, away from other cars when you arrive, but there can be lots of comings and goings of other cars / inconsiderate parkers while you're away, and people squeezing past your car with large suitcases and bags, increasing the risk of damage.
I had my previous car damaged at Stansted airport by some T0$$€R opening their door onto my car and leaving me with a nice ding in the door. I know a ding can be easily repaired, but it really p!$$€d me off at the time, as it was the only damage on an otherwise unblemished car in nearly 4 years.

Whenever possible, I now try and arrange a lift to airports to avoid having to leave my car in the danger zone!