I'm similar to Weasey in that I've done very few diets- just S&S and I did Rosemary Conley/low GI a few years back. I lost 4st on it but half of that came back when my life changed.
I've alwasy been overweight/obese- I am right now at my lowest adult weight ever. My heaviest I was 21st, at age 19. When I was 26 I weighed in at 16st 10lb so somehow I had lost some weight but not on a 'diet', not on an actual plan. I think I would have times when I could get through 4000 cals a day and some periods where I would be more careful, choose the lower fat option and limit portions but not in any meaningful way. I was also a vegetarian at age 14 and lost a fair bit but I didn't weigh at any point so it mayhave been a stone, or 2, or 3! Who knows. Then started back on meat and went up and up to my highest weight, which I do know because I was in hospital for a gynea visit die to PCOS and loss of periods and the nurse had to weigh me twice as she didn't believe someone my age could weigh that much. Should have seen it as a wake-up call!
I did like doing the Rosemary Conley, I didn't really follow the plan just the rules set (1400 cals a day for me, everything less than 5% fat, low-gi choices) which lead to me finding about 10 meals I knew I liked and would have. So not really following the diet but in my mind I was. Also a ton of exersize which I loved, I can't wait to finish the VLCD and up my cals so I can do some serious exersize again. My two attempts to do some on this have been disarsterous!
Oddly enough I'm now finding out more about other diet like Dukan, Atkins, Paul McKenna etc whilst on S&S. I never looked into any of them, I needed to change and picked this route but had I picked up an Atkins book I'd probably be on that! I'm searching for the ultimate maintenance plan- either the Rosemary Conley Low gi route, or a low carb/Paleo/IPD route but whatever it is I will be using the Paul McKenna book.