I've stayed at the Park Hyatt Tokyo a number of times. It is my favorite hotel in the whole world. The only large/chain hotel I have found to have better service was the Oriental in Bangkok, but the PHT trumps it in terms of general cool.

As for the New York Grill, I agree with Kanetaka-san: "The view is so amazing that it makes you forget about the food". Never mind, the food isn't bad, it just isn't as impressive as the ambience and view (and even the service, which is quite respectable). I've had many a memorable evening with friends there, usually for drinks and cigars, the top line of civilization, in my opinion.

Now, if you want good food in Tokyo, no shortage of that. Second only to Singapore as a foodie paradise. My favorites are the Wakiya in Akasaka, and the Rakutei tempura, also in Akasaka. For excellent value for money, the best sushi in town is Sushisei in Tsukiji. The equivalent meal in NY would cost you 3-4 times as much.