The best way to lose weight and keep it off is a lifestyle change. Any "diet" will just be a temporary solution until you decide to stop the diet and return to your lifestyle.
I tried every diet in the book and eventually gained more weight then I lost. I slowly ballooned up to 240 pounds. When I switched to a whole foods plant-based diet, which is my permanent lifestyle, the weight came of quickly and has stayed off for years. At present, I am working on getting my six pack to show which is something I never thought I would have.