i am the wife of a smoker, and i would not trade it for any other addiction. i may not like that my husband smokes, but at least i know this is something that is kept out of my house. who can say if it would be like that with other addictions?
also, again as the wife of a smoker, i know that you can NOT force someone to stop smoking. when and if they are ready, you can be there to help them through it, because they will definitely need a lot of support. but thats about it. guilt tripping them will only get you upset, and thats about it.