I'm a smoker, I like it, am aware of the consequences and understand that other people may not like it...

To go back to the original question:
Kuala Lumpur is one of the worst in Asia. I walked into the smoking lounge there and walked straight out again because it was too blue with smoke.

As far as the USA, IAD must be the worst. Again, I walked in their general smoking lounge and thought of writing Benson & Hedges to 'adopt' the site to install a good ventilation system as there isn't one at the moment - again I walked straight out.

Some information for smokers... In the early 90's I did a Burke&Wills (= Australian for a 'survival trip') around Cape Melville (Charlotte Bay/North Queensland). I got stranded flying a microlight trying to get to Cape York. In the process I ended up talking with a marine biologist in the area who had been studying turtles on the Qld islands: Many biopsies on dead turtles show a massive amount of cigarette butts in their guts that stay there and make them become a statistic... Since then I have not thrown away one of my butts. Via storm water they end up in water ways from cities to the ocean. Something to be learned here, also as far as throwing out anything else on the street...