Agree with LHR - worst airport I have the displeasure of using. A few more:
- Toilets either closed for cleaning or open and dirty
- Sneering check-in staff - especially if you are politically-incorrect enough to hold a C ticket, flash a gold card or just look like a business man
- Having to pay for wireless LAN in "executive" lounges
- Fast track security that isn't
- Arriving as a non-EU citizen and being treated like cattle
- Smelly and unwashed non-pax seeing-off or meeting their equally smelly and unwashed next of kin. (Especially around the entrance to security in T3 deps.)
- Moving walkways that don't - but you walk onto them anyway wondering if some clever sensor might set it going. Of course.. you should have known better. But you carry on... "stiff upper lift chaps, this is England"
- Ceiling panels that are missing, light bulbs dangling from threads, and patronising posters spouting how BAA are investing millions on improving things
- Never enough staff at the underground station to help happless visitors who had the audacity to arrive in the UK without enough coins to feed into ticket machines that are displaying "EXACT FARE ONLY" because staff were to lazy to maintain them.