I'm no expert by ANY Means!! I've been following South Beach pretty closely for the last month and a half. I've lost 20 lbs so far also and for the first time, I know I'll keep this off. I like that system because he explains not only what foods to avoid, but combinations of foods to avoid and the whys of it that I never thought of before. He's big on clean eating too. Fruits and veggies are great, sugar and the wrong kind of carbs are bad. Yada Yada Yada.
My problem with Weight Watchers is the whole group therapy thing. I just don't have time now to spend on myself, much less extra time sitting around listening to other people whine. (No offense meant to anyone here!) I've got three kids that can do that - and for free!