Varenicline
"Been smoking for 10 years now; and have had absolutely no will power to try and quit. 
Tried many methods; patches, mouth spray and so on; but to no avail. Only on day 8 of Champix, but, from smoking almost 20 a day, I'm now down to 2 cigarettes a day. And even with 2 a day, I can only smoke half and then the other half a few hours later. The taste is God awful and I don't even want the cigerette, it's just habit! 
The only side effects that I have had are nausea if taken on an empty stomach, and quite a few bad mood swings! But, the body is adapting to a new medicine so it's quite understandable!
I'd recommend to any smoker that has tried other alternative methods first; absolutely brilliant."