That Seaport hotel is GREAT for the cruise boarding,but isn't near any attractions or even really near many restaurants. Downtown Hilton is best located. The Canopy is new and also well located. Onyx is near Boston Garden and the Italian North End. Doubletree is near the theater district
Any other Hilton with "Boston" in the name isn't going to be walkable to anything or is in decidely non-tourist areas. This includes the airport location, the Hampton Inn in Cambridge (ok, a longish walk), and definitely not the Crosstown or South Bay locations