Bumping this ancient thread to add a word about WW...
Like any other plan, it is what you make of it. I did the Flex plan a year and a half ago and lost 24 pounds. If you truly follow the plan, there's not much room for junk - you have required dairy, veggie, fruit, protein, whole grains and oil servings, as well as an activity requirement. If you get in all of those, there are very few points left over for junk, at least if you don't have too much weight to lose. Sure, some people abuse the program and eat nothing but (small amounts) of junk, but that's not a problem with the program, IMO, it's a problem with the people choosing to ignore the guidelines in favor of eating junk. That's just as much cheating as eating too many points is.
The reason I'm here if WW is such a good plan? Well, I quit following the plan after a while on maintenance. Figured I could just follow the guidelines without counting points or journaling, and well...um...yeah. So that didn't work - I devolved into fast food all the time, no exercise, and just generally really bad habits. This time around, I really don't want to obsess about food, points, servings, etc., and that's what I did on WW. It worked great - and I still was able to eat the occasional snack pack of doritos, or a small portion of m&ms without "cheating", even though overall my way of eating was much, much better than your average American's. I'm still not sure I'll ever get to the point where I don't want those things occasionally, which is why I'm skeptical about the "doability" of South Beach. But here I am, because I don't want to obsess and count every little thing. I want to go to a restaurant without looking online for nutritional info first so I know what I can order.
So that's my novel...WW isn't inherently a bad plan, IMO...but you have to follow it. If you're not getting your required servings of healthy foods in favor of junk, even if you stay within your points allowance? Well, you're not following the plan, then, and it shouldn't be a surprise if you don't lose weight.
Back on Phase I as of 7/8/09 after a REALLY long time away...