Food Replacement Diets

I need to start a diet and exercise plan. I am not too overweight (5'7", 165 lbs), but my Dr. Pepper and cigarette diet isn't cutting it anymore.

90% of comments i read here really impressed me...
are you really strict with how much calories you eat in a day? i personally dont like the ideas of "diets" and that kind of things, i simply dont eat fried things, meat with fat (i dont even like how fat tastes), candies, chips, etc. and of course, exercise. you dont really need to be counting those calories, its just common sense, eat vegetables, eat fruit (not a lot, and no more than 2/3 bananas a week), eat meat (all kind of meat), and more that i cant say in English (not my first language).

Edit: SFK i love you (dont read what i said before :P)

Not read all the replies, but basically try something that's balanced and you can maintain in the future - changing your eating habits. If you do something extreme like meal replacement products, only eating protein, only eating soup etc. when you switch back to eating normal food again then if you haven't changed your eating habits you'll gain the weight again.
A nutritionist would be a good idea, or just write down everything you eat over a 3 day period then look through it honestly and decide what you could replace. Exercise would be a good idea too, as other people have said - gives you more leeway in what you can eat.

how about pure white gruel ?. it work for me