Youth Hostel
Am Knüppchen 2
Map - located in the fortress "festung ehrenbreitstein". from there you have a nice view over koblenz
Rhein-Hotel Diehl's Terrassen
(http://www.diehls-hotel.de) is situated directly at the rhine, below the ehrenbreitstein castle/fort, with a view of the deutsches eck from every room. 4-star, but unfortunately only a few metres from a busy railway.