Could you imagine anything more excited, romantic, unbelievable than to spend Christmas in London. I would definatly get ahold of a travel agency and ask them any questions you have about traveling there at that time. Good luck whatever you do and have a wonderful Christmas no matter where you are.
I think that visiting london in the summertime is the best idea. this is what i did. the weather is much better, and the activities endless. Either way do the Jack the Ripper tour
i believe that xmas in London would be exceptionally spectacular and very beautiful . I also believe that xmas in LOndon would be wonderful and full of excitement.
I would say if you have to choose, Paris at Christmas would be a bit prettier. They'll both be as chilly, but if you want that cozy, pretty, romantic atmosphere, you should take to Paris at Christmas instead.
It's a spectacular city any time of year, and really special during christmas. However, needless to say it's freezing there at that time. I don't mind the cold so I'd go for it, but take that into consideration.