A hard question to answer since part of determining the best hotel is dependent on what you want to do. Will it be a special, blow out kind of trip? Will you be intending to use public transportation? What do you think you will be doing and where are those venues? In general, you can't go wrong logistically with the Trafalgar or Waldorf. Waldorf wins if you want an executive lounge, I haven't stayed at the Conrad yet, but it's on our list. Mrs. xooz and I love London and go frequently, but we try to do it on the cheap. Since this is a special trip for you, you may find the more upscale or centrally located hotels as a better option for this particular trip. Bottom line is that London is a fantastic place to visit, so for a first timer, don't be afraid to spend a little more for convenience. Hope you have a great trip!