Off the top of my head, the two most common airport/airplane smells are:
1. Burnt Jet Fuel
2. The mixture of bad coffee and lavatory kool-aid that is stuck in airplane upholstery
LAS smells like the race track. Stale cigarettes, cheap beer and cheap beer that's been pissed out on the carpet.
You smell those!?
... and the seats of the plane as you get on ...