Hotel Recommendations Paris and London

[Cruisinthru]

DH and I are booked on a cruise that leaves out of England in September 2010. We are planning to spend a few days in Paris prior to the cruise and a few days in London after the cruise. We have never been to either city. We need to find comfortable, safe, reasonably priced hotels in both cities. Because we are staying just a few days in each place we would like to stay in areas close to tourist attractions or near subway, etc. Does any body here have any recommendations?