Diets: Which ones really work?

I can’t post much this morning as I have to get ready for my first day at my new job.  I’m really excited and I can’t wait to start.  I did a short yoga sesh this morning to relax my body and mind and get ready for the big day.  I then dug into a big bowl of oatmeal with my new addiction Sun Butter.

For my one of my fundamentals classes I have been doing some reading on various diets including Macrobiotic, The Blood Type Diet, Sally Fallon Diet, The Atkins and many others.   I now am looking for some feedback on what others experiences are; what kind(s) of diet(s) have you tried? What was your experience? Do still prescribe to a set diet or do you have guidelines that you follow?