As a non smoker, I've always found the actual smell of a burning cigarettes to be sweet and attractive. I think this is because some of my earlier memories are being a little boy waiting for the bus in freezing cold Russia, and seeing soldiers smoking. It looked warm and pleasant, so I think I associated the smell with pleasure.

Places with stale smoke, like bars and smoker's houses still smell bad though. Its the actual smoke from a cigarette that I like the smell of.