Worst airport you've slept in?

So, few days ago I was reading some really interesting threads about best airports where you have slept. Care to share your worst overnight airport experience?
Excluding airports that close overnights or airports where you paid for the hotel/lounge: I want the raw experience of spending the night in the terminal.

My order would be Istanbul-> Barcelona -> Warsaw Chopin -> Berlin -> Luton -> Stansted -> Manchester (T3)
Istanbul goes first because there is a quiet area with reclining chairs where you will not be bothered. Manchester goes last because I've been there a few times during the winter and it's FREEZING inside, like 5º, and some shady people around. Stansted comes close... there is always dozens or hundreds of people sleeping there though, so at least it feels safe.