The description of that Sheraton (formerly the Sheraton National) as being in Pentagon City is grossly misleading. It is separated from Pentagon City by a 16 lane interstate highway, a light industrial area, and a good sized hill. I am not certain if it is even possible to walk from the hotel to Metro without spending at least part of the walk on a road without a sidewalk. Based solely on geography I would not recommend it as a base to go see the typical sights.
Of the other three you've listed, all would be better choices. If prices are equal, I would probably strike the Hyatt Regency as it is comparatively far from Metro (I think about a 10 minute walk), and focus on the other two. The Key Bridge Marriott is an older hotel (see a current discussion about it on the DC forum), but it is walking distance from both Rosslyn Metro and Georgetown. The Marriott Wardman Park is in D.C., but in a quieter, more residential part of Northwest Washington that is a bit removed from some of the hustle and bustle of the city. That said, it is close to a Metro stop and walking distance to the zoo. As between the two Marriotts, I'd go with the one that offers the better price and/or the amenities you most want in a hotel.