The best diet out there is one where you simply eat healthy foods in moderate portions. Be sure to eat lots of veggies, and cut down on sodas, and high sugar/fatty foods. It also helps if you can exercise regularly as well.
Diets that drastically cut down on calories rarely work in the long term, so it's only by permanently changing your eating habits that one can keep to a healthy weight.
Atkins doesn't really sustain weight loss in most people. In the beginning it's really strict and everyone I know who went on it failed, some got sick on it. You need carbs but the right ones like whole grains and fruits and vegs with carbs. Stay away from excess sugar, salt and fat and you'll lose weight. Maybe slowly but you'll keep it off and you won't be yo yo dieting or doing fad diets. Good luck!