I think WW would be the only weight loss program I would pay for (the only truly effective one, for the long run, in my opinion).
Of course, the concept is rather simple. Exercise more; eat fewer calories. But WW throws in the support group, which is important.
You can look up the point system online and get the info for free though if you don't need the support group. You can learn how to eat better without paying.
Then again, there are a lot of online forums that offer more 24/7 support and are free. I have one friend who swears by
3 Fat Chicks on a Diet Official Website for Weight Loss Support - Home (something like that) and I perused those forums when I had more weight to lose. I never got terribly involved, but I think the concept is good. You get lots of tips and support. (Then again I think my friend used the forums in conjuction with WW, now that I think about it).