I second the Chantix recommendation. I've been smoking for about 10 years, roughly a pack a day, give or take. I've tried everything from quitting cold-turkey, to patches, to gum... NOTHING worked for me. I'd be able to quit smoking while I had the nicotine replacement, but once I ran out of patches/gum/etc., I was back to a pack a day almost instantly. My doctor just prescribed me Chantix, and I'll start my first week of a 12 week program with it this Friday. I'm being told to keep smoking (if I want to) for one more week, then the medication is supposed to take over. I've been talking to a LOT of ex-smokers recently, many of whom smoked for 25 years or longer, and every one of them that stayed on the medication for the full 12-24 weeks have successfully quit, and stayed quit after the medication was gone.
Since it's not a nicotine replacement therapy (there's no nicotine in the drug), after the prescription is gone, you've completely ruled nicotine out of your system. The habit may still rear its ugly head for a brief time, as WeedHound pointed out, but that's far easier to beat than the psychological/physical addiction. I'll keep my fingers crossed for you, and hope you'll do the same for me.
