I'm a huge fan of Weight Watchers. I did it for the first time around 5/6 years ago. I moved to the States from England and my weight ballooned due to the complete change in life style (eating out every week and virtually no walking). I stuck to the plan very well and the weight just fell off. I got down to 140lbs (I'm 5'7) and looked the best I ever have as an adult. I've just had my second baby (well, 9 months ago!) and so I’ve signed up again. The thing that I like is that no food is off limits. I can eat whatever I want, as long as I stay within my points. So, I could go to McDonalds and have a Quarter pounder meal if I wanted. It would take up pretty much all my points for the day, but I could do it. This made it feel less like a diet to me. It was a huge learning experience for me too, as I discovered that foods I thought were healthy were actually not.
I could go on and on but I think you get the point. Try it out. I think you can sign up for a free one week online trial (I did my 100% online). See how you like and go from there.
Good luck.