The real question (which archy mentioned) is what happens after the couple of days that you stick to it? Do you mess up once, and decide to "start over next week," or give up? I've seen the "all-or-nothing" attitude prevent a lot of people from losing weight.
I can only stick to very healthy eating for a couple of days. So I plan treats every few days: a mini candy bar, or one scoop of ice cream, or a can of non-diet soda, or whatever I'm in the mood for. I also have rest days where I don't exercise... some people say it's good for your body, and it's good for me, mentally, to have a break. Make sure whatever you're doing isn't too strict... you'll probably be following some form of it for the rest of your life!
As lenient as it is, I can only stick to my food and exercise plan for a couple weeks at a time before I "mess up" in a bigger way

and get a burger and fries for dinner, eat a big dessert at a restaurant, skip a planned workout because I just don't feel like it. *THIS* is where I used to have problems... I'd skip a workout, then skip the next, and the next... or I'd eat breakfast from McDonalds and figure I blew it, so I'd have cookies for lunch. The reason I'm (slowly and) steadily losing weight this time is that I've really been working on my "comebacks." I'm trying to go back to doing the right thing as quickly as possible after I slip up. And it seems to be working!
As for specific plans, right now I'm actually not following anything, but in the past I've counted calories and had great success with that because it's so flexible.