My folks went cold turkey about thirty years ago, following my dads heart attack at age 39. I have a huge amount of respect for them knowing the fortitiude it required to do so.
I have some pals that are now smoke free for several months now using the electronic inhalers. They love those things. I gotta admit they smell a lot better.
After cleaning up my parents ashtrays and getting stuck in a closed up car with them (they chain smoked when they drove), it cured me of ever wanting to try it myself.