Grand Hyatt Tokyo, Japan
Upscale hotel in Roppongi Hills, slightly below the top-tier segment. Busy and with plenty of rooms, it's still a great place to stay and service is swift, friendly and efficient. Good location despite being a few blocks from the nearby subway station. A personal favorite of mine.
If you want to venture outside for breakfast, try Lauderdale just across the street from the Grand Hyatt main entrance. Great place, be sure to try the smoked salmon omelette. Delicious.
There's a Tsutaya book store nearby with a Starbucks inside it, open every day from 7am to 4am. They allow you to get a cup of coffee and browse through any magazine you want, for free, while staying at their premises. Exit the Grand Hyatt main entrance, turn left and follow the street past the Louis Vuitton store, the Tsutaya/Starbucks will be on your right-hand side after a minute or so, right at the corner.
Be sure to head up to the Mori Tower Sky View top floors late at night for some mesmerizing views of the never ending Tokyo skyline.
Tokyo Midtown is nearby, too, sporting an upscale mall, nice ambiance, and the Ritz-Carlton Tokyo hotel.
Grand Hyatt is part of the Roppongi Hills complex. Head for Roppongi Station and follow the signs first to Roppongi Hills, then to Grand Hyatt. Arriving from the main Roppongi Hills area is slightly confusing at times, sending you through a ground floor back entrance, so you might want to follow the road and arrive at the main entrance instead.
The Azabujuban subway station is fairly close by too, and the walk between that station and the hotel through a couple of back alleys is typically a pretty pleasant experience.