Our tour group was booked at Keio Plaza Hotel for 1 week. It was a long drive from Tokyo Narita, about 1 1/2 hours in the mid-afternoon. But I was quite impressed with the location, the room itself and the amenities. There was a nicely maintained fitness center (which I went to almost every day), a spa, loads of restaurants and a big, spacious lobby.
It is in West Shinjuku, surrounded by nice office buildings and across the street from the Tokyo Metropolitan Government Building. It is close (very walkable distance) to loads of shopping, restaurants and bars and to the Shinjuku Station. As part of the lodging cost, we received coupons for complimentary breakfast, which we could use at 3 different buffets---which were all extensive.More