I had the same not a diet but a lifestyle modification, dieting isn't rocket science, eat fewer calories than your body needs and you will lose weight. Of course the healthier the food the better since fatty-junk food doesn’t fill you up. I restricted myself to a 2000 calorie diet, made up of healthy foods that I like. I had to ditch all fast food and pizza which hurt but after doing this since last July I don’t miss it anymore. The key to it is to still enjoy what you eat, I bought a scale at Target for $20 and I measure all my portions, you will be surprised what 1 serving of most food is. Also I exercise at least an hour each day, again the more fun you make it the better. The gym I go to has TVs on each treadmill and elliptical, or I listen to my ipod and just zone out. It's made me a much more relaxed person at work and home, not to mention the health benefits are a major plus.
My goal loss was 85 lbs and as of today I'm down 94 lbs which is what I weighed 17 years ago in college.
Here is a good site about fitness and weight loss that I found in a thread here on TFP
http://exrx.net/Beginning.html
Good Luck!!