The Park Hyatt in Milan is the best hotel I've ever stayed at. My room was gorgeous. (As a Hyatt diamond member, I was upgraded to a deluxe room, which is about 10% larger than a standard room.) The marble tiling in the spacious bathroom provided a luxurious feel.
The lounge area of the hotel is beautiful. It sits underneath a large cupola, which lets in natural light.
Service was excellent, as it is at all Park Hyatt hotels I've stayed at. The bartender was knowledgeable and sophisticated and made good drinks. The restaurant is Michelin starred, and my meal there was good.
The location--steps away from the Galleria Vittorio Emanuel II and a block from the duomo--is impossible to beat.