I've been posting on here for a while and I've seen lots of questions regarding different types of diets. I personally do not diet, but my best friend has had much success with a blood type diet. I haven't seen that mentioned on here, although I may have missed it. I'm not really sure what this diet entails - she basically explained that it offers different eating habits based on your blood type. I haven't researched it it, so I don't really understand how it works, but I thought I would mention it on here. She has been following the blood type diet for several years (as well as working out regularly) and she has lost a pretty large amount of weight (I believe somewhere around 70 lbs).
Like I said, I haven't tried this diet myself, so I can't deny or confirm anything. But it worked well for my friend.