I've done WW 4 times in the last 11 years. I always follow the plan and stay in my points and I see results. I usually lose at 20 pounds in a couple months. Then I slowly go back to my past way of eating and gain all the weight back or even more.
This year I joined again and liked the new Point Plus system. It never seemed right that cookies could have the same points as fruit and I would always chose cookies or whatever. This time I dropped junk food completely and it has been 3 months and I lost 40 pounds. I don't really crave the junk food anymore now and I think that was part of my problem in the past.
Being on any diet should help you learn more about nutrition. During my research I found people discussing the Paleo diet. I studied it for a couple weeks and got Robb Wolf's book. At first I was scared of giving up certain foods. After removing those foods and increasing my vegetable intake even more, I feel better than I have in over a decade and I still lost 10 more pounds. And this is after just a few weeks. I would recommend Paleo to anyone. There is tons of support online and many sites with great recipes. The food is never boring and tastes great.