I've found slimming world works well. I can eat normal family meals like spag bol, curries, stir fries, chilli etc with just a few tweaks. I have fruit, oats and yoghurt for breakfast and a big salad with eggs and chicken for lunch and eat fruit. I have a snack of ryvita and cottage cheese when I get in from work. I'm a bit more relaxed at weekends, depending on what we are doing.
I've lost just over 3 stone and kept it off for about a year. I really like the fact that my meals would not look particularly diet-y, and I can eat a plate full of food which fills me up.
I could probably lose more weight on a stricter plan but I look at it as a lifestyle not a diet, and I know I can maintain this.
Going to weigh in does keep me on track too!