I recently stayed at the Marriott Waterfront and Renaissance Hotel in Baltimore, MD. The hotel was really nice; spacious rooms, nice amenities, and a good in house restaurant. The food was expensive in the hotel, but that's pretty normal for any hotel of that size, but it was very good and the service was excellent. I had a room with a great view of the harbor, and the location provided easy access to many local attractions within walking distance. Camden Yards baseball park was only a decent walk away as was the football stadium for the Ravens. Sadly, neither team was in town while we were there. Many good restaurants, however, were also within easy walking distance and a mall was nearby as well. The city of Baltimore is surprisingly very nice, too. I hope to revisit it before I die and take more time to see it.
There is also a harbor "taxi" that will take you to several different stops at a very modest cost. I didn't personally get to use this service, but some who I knew that were with me did and enjoyed it very much.