Best Ways to Quit

So i am interested in what is the best way to quit an addiction? Is it cold turkey or should you gradually quit the addiction? If anyone has any ideas i would be really interested...

Addicted to Alcohol

Addiction is constantly on my mind. At 23 years old i am starting to realize that the fun i was having in college has caught up with me now that i have graduated. Worst of all i cant break the cycle because that would mean leaving behind the best friends i have ever had. I wish i could handle having one drink at a time, but i now realize that my family history of alcohol addiction is in fact genetic... it just has to be. My grandfather, father, and I are all hardworking people who like to have a drink at the end of the day, like alot of people out there. I am pretty sure i can handle one drink, but that second one always turns to five.
To fight my addiction i started working out more, but i now find that i am getting addicted to that. I visited www.addicted.com and was soon aware how many people are suffering with much worse problems than I. There are several statistics that show a large portion of our population is searching for the same answers as i am. I have heard something like 25% of the people suffer from addictions.
My question is simple? When is something an addiction, and when is it just part of your life? Is it all genetic? is it weakness?
I have to be hard on myself and realize that it is probably just human weakness, we are far from perfect. I realized yesterday, my first day sober in over a year and a half, that i am stronger than i think.