Smoking gets the top spot on turn offs for me. It just show a total lack of will, self control, self respect, intelligence and independence.
By independence, i mean that most smokers i know started because of peer pressure.
That s*** smells so bad. Had someone paint the outside of our house a few weeks ago. Went once inside to go to the bathroom. The smell stayed for the remainder of the day. The hotel where i work uses a ozone air purifier (Which produces a toxic gas and needs lots of airing out after use) and lots of citrus deodorant to get the smell out of the rooms. Even smokers don't like the smell of other smokers. Around here the new fad in new hotels is to make all rooms non smoking. Less work for housekeeping, maintenance (ew a yello air filter) and reception desk people (when you rent all non smoking rooms first... the next one aren't that happy, mostly the asthmatics)
Restaurants do that too; simply because people leave when there's no non smoking tables available. Every place who has turned non smoking has turned out more business in medium term (less than 3 months)
The only member in my family who has smoked stopped about 10 years ago, now has pulmonary fibrosis. He'd be probably dead by now if he hadn't stopped.
EDIT: Smokers who died because of their habit go in special hell!