London, absolutely. I'd do a lot of visiting battlefields and rummaging around in meadows. I'd visit York, Bosworth, Tewkesbury, Eltham manor, stop at Harrods, visit Senlac Hill (Hastings), and really do a hell of a lot of touring, yeah.
I have my passport but have never managed yet to get to England. One day!
Some of those places you listed are a bit far from London.
By American standards, no place in a European country is "far" from any other place within that same country (with the exceptions of Russia and Norway, Sweden, and Finland).
Ukraine, France and Spain are bigger than Sweden, Norway, Finland. Germany is roughly the same size as Finland.