I'm down about 30 pounds since last Summer, and it's had sticking power. I went from a few pounds over obese on my BMI to a normal BMI weight (200 lbs to 170).
I'm a data-driven guy, and I started using a phone app where you scan barcodes, or manually enter your food and weight. I got a scale off amazon for like $10. Before I even started changing my diet, I just started entering everything I was eating and drinking. It was a bit eye opening. The calorie count was too damn high. Lots of carbs, cheese, and alcohol.
I didn't follow any specific diet or anything, but I tried to keep my calorie count around or just under 1500 calories per day. If you're trying to meet a calorie count and not be hungry all the time, you figure some stuff out. You can eat a lot of vegetables. You can eat a decent amount of seasoned meats. Pasta and bread are things you can only have a little of. Drinking alcohol ruins the day.
Anyway, sticking to the count, I watched 1-3 pounds a week drop off and stay off. It was very satisfying. Math. Data. Measurable results. I recommend it.