Personally I'd go dietician - you want to lose it slowly and safely.

I put on weight with Weight Watchers & Jenny Craig - seems my body doesn't like highly processed, artifical foods like the the ones they recommend (I swear my body sees the words "weight watchers" and bulks up) - I find eating, natural foods, cooking from scratch, snacking on healthy stuff during the day, not having junk food in the house, dishing up on a smaller plate - is the best way for me to lose weight.