Hi LittleBike,
Sorry I didn't get this sooner. But I haven't been back to London in years. One thing I recommend though is that if you are into photography one of the fun things my friend and I did was to just hop on and off the buses at night and did a night "photo tour" of the city. Of course i loved the picadilly circus area. Camden market for shopping. There's just so much to see and do.
Hope you have a great trip!