Bupropion
"I started on Bupropion about 3 weeks ago. On day 1 I had more energy and felt happy; I even didn't feel like smoking-the urge was decreased a lot. By day 10, I was down from 2-3 packs a week to 1 pack or less a week. I switched to brand Wellbutrin XL and even though my cravings were nonexistent on Bupropion, the brand name drug, Wellbutrin didn't curb the cravings as much. I also noticed my energy level decrease a lot. I'm going back to Bupropion because I literally smoked the few cigarettes I went down to purely out of habit because I had no cravings at all. It was amazing how quickly it worked. For me, the purple generic pill worked like a charm, and my mood improved  significantly.  I wish I had known about this 9 yrs ago!!!!"