It depends if it's a ban on just cigarettes or nicotine in general. Ban a drug, and you'll create a black market for it. Ban a method of administering a drug, and you can move it to other safer or more socially acceptable methods of application.

I personally hate smoking. However, as far as I am concerned, it's down to the individual, so long as they are not affecting me, and covering the excess social costs (via taxes).

Unfortunately, most/many of the cigarette smokers I encounter are of the inconsiderate type. A single smoker can cover a large area in smoke, and most don't either notice or care. I have yet to see a viable method of stopping this, other than banning cigarettes.