Like jetta and LS, I prefer the aisle seat for long-haul flights
as it makes going to the john a lot easier. You also get
"unlimited" elbow room on the aisle side of your seat. The price
you pay is that people and service carts roaming the aisles always
seem to bump into that protruding elbow; you also have to put up
with the occupants of the middle and window seats having to wiggle
their way past you to go to the toilet.
For short-haul flights of under three hours, I generally prefer a
window seat for the view.