I would say over 95% of diets out there work.  I do
question ones health on extreme diets that
adervitise losing 7-10 pounds per week; when a
healthy weight loss should be no more than
2-3 pounds a week.

The problem with the word "DIET" is that you can't
stay on them forever.  One could end up with serious
health issues staying on an "Extreme" diet over the
recommended length of time.  

Forget the diets, forget the calorie counting unless
you're a professional athlete.  How about a lifestyle
change.  Make a decision, a promise to change the
way you're eating, to excersie consistently, to have
a new LIFESTYLE on your own health.  

Start by a decision.  Write your goals down on a
3 x 5 card and place it on your bathroom mirror.
The goals should be:
How much do you want to weigh.
When do you want to achieve the new weight.

Be realistic on the time issue.  You shouldn't be
losing anymore than 2-3 pounds a week after your
first 2 weeks of your new lifestyle.

Take a head to toe photo.  Take measurements of
arms, chest, waist, hips (if female) and thighs.  Get
serious, take your lifestyle by the horns.