There is a Starwood hotel in Sapporo, the Sheraton Sapporo. I did not stay there, but drove past it enroute to the Historical Village of Hokkaido. If you are debating one versus the other, it is useful to know that the Sheraton is adjacent to the Shin Sapporo train station. This is a stop on the express train from Chitose, and is the stop before Sapporo. It is only a few minutes by train into the center of town, but it is at least a 20 minute taxi ride.

I have no personal opinion as to whether one hotel is better either in terms of service or location than the other.