Jester: Hendon is a bit of a detour inside London, well, the tube connection there is not so nice. But it's worth it! Ohh, and they have a Vulcan there.....arrrfff!
But the top IMHO is Duxford.
HMS Belfast is also great fun, I remember that even my wife enjoyed it quite a bit.
The IWM is great as well, and it's within walking range from Belfast...if you have good legs. (had to, there was a tubestrike and my wallet was light)
Haven't seen HMS Victory yet (Portsmouth) so I envy you absolutely when you beat me to it
