Well, it is well researched fact now that excessive carbs intake combined with a lack of exercise is what makes most people fat.
So one of the easiest ways to lose fat is by limiting your carb intake by 5%-10% of your daily calories and limiting your daily calories to maintenance-500cal.
Yes, that means cutting out all liquid calories (soda) and all the grains (bread, cookies, pizza) and starches (rice, potatoes, etc) and replacing them with decent sources of protein and fat such as grass fed meat, wild caught fish, pastured eggs and so on. Check out
http://www.archevore.com/get-started/ for details.
As for exercise, there are plenty of studies that show that excessive exercise may be harmful and may actually prevent the weight loss. Do not exercise for the sake of exercise, instead find some activity that is interesting and fun - do zumba, do Frisbee golf, ride a bike in the park, something like that.
As people mentioned previously do some things while you play WoW. Did a daily? Do a 5-10 push-ups before turning it in. Died on a raid boss? Do 20 jumping-jacks.
Flying from one place to another? Do 20 squats. You'll be surprised how much things you can do along with your usual gaming.