4-10-30 Takanawa, Minato, Tokyo Prefecture 108-8611, Japan
Airport limousine from Narita drops you at the hotel doorstep.
There are many "Prince" hotels in Japan, I noticed. The Japanese have a lot of "Prince Syndrome" I suppose?
Shinagawa Prince was the very first hotel we stayed at in Tokyo in Winter 2008. My reason for choosing the hotel? Yes, you are right - it was just right in front of the JR Yamanote line, and the Shinagawa station also has direct train connections to places outside Tokyo like Yokohama and Kamakura. Even one of the Shinkansen lines pass through the Shinagawa station, although we did not have the chance to take it unfortunately. Hence the station is relatively huge (although not as ginormous as Shinjuku), with a number of restaurants, convenience stores and supermarkets.
Shinagawa Prince itself is a HUGE hotel complex. Besides several hotel towers, the amenities include an aquarium (!!), bowling alley, shopping mall, and multiple restaurants (including sky dining which we tried and was good!). Of course the shopping and dining is nothing to shout about and mostly expensive stuff, but it is like a little city in itself. Probably they are trying to compensate the fact that there is really nothing much to see around Shinagawa as it is mostly a quiet business area. If you want non-stop fun and excitement at your doorstep, it is better to select a hotel in the Shinjuku, Shibuya or Ginza areas.
There are several categories of rooms at Shinagawa Prince. The smaller and older rooms are in the North and Annex Towers, but they are also far cheaper. I wanted a spacious new room on my very first Japan trip so I forced Samurai T to pay through his nose for an upgrade to the Main Tower, where all the rooms were bigger and newly refurbished. I remembered it was about SGD 315 per night (no breakfast), but oh my, it was worth every yen!!!
Our room was on the 35th floor, and we were greeted with a direct view of Mount Fuji every morning (depends on the weather, but in winter the days are usually bright and clear). I don't know what bed they had, but you could sink into it and never wake up. It was a standard size room that I have come to expect in Asia, but in Japan, the room was considered LARGE. There was a flat screen TV with a CNN channel and LAN Internet access (think you have got to pay but we did not use). The toilet was also clean, bright and big. Service from hotel staff was ok, but then again, Samurai T and I are never fussy customers. An interesting thing about Shinagawa Prince was their "Green Day" policy. If you choose not to have the beds made nor the bath towels changed everyday, they reward you with a 500yen (SGD 7) voucher PER person which you can utilise anywhere in the hotel. You get to be environmentally friendly and EARN money at the same time! How cool is that??!
To be objective though I have read a number of complaints on Tripadvisor especially those not staying in the refurbished section of the Main Tower. Breakfast buffet (which we did not try) was apparently not so good, and you have to pay if you wanted to use the swimming pool (huh!). Although it is a 2 minute hop to the train station, the ride to Shinjuku is about 15 to 20 minutes. You also need to go to another station to connect to the Tokyo Metro if necessary. And yes, there are indeed many cheaper alternatives around so weigh your options carefully.
My recommendation? If you have the moolah to pamper yourself with a Main Tower room, please go ahead. If you are using Tokyo as a base to travel out, Shinagawa is also a good location. If you want to save your money for shopping, then there are many other available options around!
You can check out Shinagawa Prince's prices at this website: http://www.holidaycityjapan.com/tokyohotels/