You can only book The Fat Duck three months in advance, they don't open bookings up until then. It's amazing but ridiculously expensive; I didn't feel like it wasn't worth it but it did cost a fortune. It's worth saving up for. I've been to Gordon Ramsey on the Royal Hospital Road and in New York, both good and a bit less expensive than The Fat Duck. If you're ever in Edinburgh, The Kitchin is really good and really reasonably priced.