Here's my opinion and advice but remember, it's just my opinion, you have to decide what's right with you. Personally, I would say avoid Exante, Cambridge Diet and all the other VLCDs. I've done them and actually, they're not great. Yes you lose the weight but you lose it by removing food completely, it does nothing to work on your attitude and relationship towards food which obviously isn't great if you need to lose weight. Because of that, I think they're quite hard to maintain. Also, the rate at which you lose means that you will be losing muscle as well as fat which lowers your metabolic rate. I think that VLCDs should be a last resort, if you've tried everything else and it's failed. And I mean really tried, not just given it a few days and given up but really tried other routes.
If you feel that you need structure, try Weight Watchers or Slimming World, especially if having a meeting and that face to face support will help you.
Personally I think that you don't really need to be paying membership fees for WW or SW or buying products like Herbal Life, you can just count your calories and do some exercise. That way you get to eat the things that you like rather than just the things that are in that diet plan. You've said you're busy, so if you plan out each day the night before or even the whole week it'll be much easier for you because you'll know what you're having and you'll be more likely to stick to it. Personally I would avoid WW meals and any other pre-prepared meals. Yes they're nice and easy and quick for you but to be honest, they're not very good for you. They're completely processed and so not really all that healthy. It doesn't have to take long to cook, stir fry takes just 5-10 minutes!
Calorie counting doesn't have to be hard, use myfitnesspal.com to track all of your calories and exercise. They'll calculate the calories that you need or you can use the links below.
Work out your BMI here:
Calculate Your BMI - Standard BMI Calculator
Work out your BMR here:
BMR Calculator (If you don't know, BMR means Basal Metabolic Rate, basically that's how many calories your body burns if you do nothing all day, just through being)
Work out your activity level here :
Harris Benedict Equation (This takes your BMR which is what you'd burn if you did nothing all day and takes into consideration how active you are and gives you an estimation of your daily calorie burn, the more active you are the more you'll burn obviously)
Each 1/b is worth 3500 calories, that's 500 calories a day. So to lose 1lb a week, take off 500 calories each day. To lose 2lbs a week, take of 1000 calories a day. I wouldn't recommend taking off more than 1000 a day and definitely don't go below 1200.
Hope that helps!