A little at a time is always the best way - a couple of pounds or so each week and in a couple of months you'll have lost around a stone. You won't notice the changes yourself, but friends who haven't seen you for a few weeks will notice the difference.
Rosemary Conley's Hip & Thigh diet is good. It's balanced but low fat, which means you can have low fat dairy produce and also a moderate amount of stuff like jellies or sweet drinks and plenty of vegetables, bread and pasta. You generally see inches disappear first rather than weight.
I'm currently doing Atkins, although not following it strictly. I've lost just over a stone since March, and that's with sneaking in the occasional chocolate biscuit or packet of crisps. Not supposed to have bread or pasta, which is a pain because I love my sandwiches and Italian food, but on the plus side, I am allowed full fat milk and my beloved cheese.
I'd suggest you find a diet you can stick to (ie one that allows a fair amount of what you like to eat) and one that suits you medically (Atkins is fine for me and my doctor's OK with it, but I wouldn't recommend it to anyone with heart/cholesterol problems).