You need to ask yourself why the other diets failed, why did you stop following them. Then I suggest you take a long look at the food diaries on here & see which you feel you could realistically follow.
Once you've chosen your diet go on the forum regularly & get tips from other members.
I'm doing Slimming World & have been for 11mths now. I don't have much to lose & the loss has been slow. However, there is a girl in our class who has lost 8 stone over the same period following the slimming world extra easy plan.
Good luck whichever you chose to follow.