Has anyone belonged to a (successful) weight loss program?

I’m looking into joining one. I used to be a part of LA Weight Loss, which worked great, but it has been closed down for some time now and I’ve gained some weight since then. I’ve been looking at a couple places (Slimgenics, Weight Watchers…) but haven’t heard anyone say much about them. Has anyone here joined either of those programs (or a different one) and had success?