I've been overweight for a very long time and had bulimia as a late teen. The best diet I've done is slimming world because it is more about leading a healthy lifestyle than anything else. Exercise has never been my problem as I have an active lifestyle, but the odd glass of wine creeps in, a biscuit here and there, a cake here and there... Slimming World allows that but with control.
I've tried lighterlife, slimfast and cambridge diets (not good for an ex-bulimic and they knew I was one!), detoxes, weight watchers (which I found too constrictive), rosemary connelly, atkins, e-diets, weight loss resources, slimming world. I had a lot of success losing some of this weight just counting calories (4 stone in a few months) at home and could easily do that again, but SW just gives me extra motivation.