Whichever you do Nikcola, why don't you join in with the mumsnet mamas, so you get to do a weighin each week and announce your loss (not your weight!) which is great as an incentive to stick with it, without the embarassment of having to do it in public.
One diet you probably haven't looked at, but which I'm finding quite easy to do as a lifestyle adjustment style diet, as Chinchilla says, is South Beach (with a few personal twists like being stricter than it suggests Monday to Friday, and more relaxed about it at weekends so that it averages out over the week!). I'm afraid I couldn't cope with counting points for the rest of my life (like WW), or having to remember whether it was a day for this type of food, or for that type (like SW), so this one suits me. Look at things like that and decide which type of system suits your personality, and you think you could stick to.