I agree with the above ... all diets work as long as you stick to them ... but once you come 'off' them and go back to eating the way you were before you were 'on a diet', the weight will reappear ... probably with a few more pounds. At the end of the day, I think to successfully lose weight and keep it off, you have to change your way of eating for good, not just for a few weeks or months until you've lost the weight. So, if you choose a diet plan that you KNOW you can stick to for the rest of your life, you WILL be successful.
That being the case, and after many, many failed attempts over the years, I've finally decided that I'm never 'going on a diet' again ... I've decided that I need to get back to basics and simply eat more healthily ... cut out the crap, convenience meals, unhealthy snacks, etc, and stick to good healthy basic foods like lean meat, chicken, fish with lots of veggies, salads and fruit. I'm no angel and obviously I'll have the occasional treat, but because I'm no longer 'on a diet' I don't feel under any pressure, and feel much more in control of my eating habits. It's early days but I'll see how it goes.
So, whatever plan suits you is the one that's going to be most successful. Good luck!
Nichola