I suspect you're not going to find anyone here who will recommend a diet plan that is under 1000 calories unless it's a medically supervised one.
I would suggest reading a lot of the many wonderful threads on this board about nutrition as well as looking in the various areas for information on the specific plans.
Are you the type of person who wants a plan that tells you what you can and can't eat? Or do you need more freedom to choose your own foods? What do you normally eat? Do you exercise at all? How many pounds are you wanting to lose?
Give us more information and we'll be happy to help guide you to a HEALTHY plan.