We spent 2 nights at this B&B over the Royal Wedding weekend - we were made very welcome and had an excellent stay.
Michael and Siobhan have immaculately restored this late-Edwardian brick house, and it's full of modern art, including Siobhan's own work (some of which is for sale). The accommodation's spotlessly clean and bedrooms and common facilities are comfortable and well-maintained. The garden's lovely and full of unusual plants. Continental-style breakfast is taken in the sunny conservatory around a common table and includes excellent home-made produce.
The house is about 400 yards from Kew Gardens underground station, with easy connections all over London: the trains run above ground at this point, but we didn't find their noise any disturbance. You can be in the centre of London in about half an hour. There are plenty of good pubs and restaurants within easy walking distance and there's a lot of interest in the area, including the incomparable Kew Gardens themselves.