Without suggesting a specific hotel, you might want to have a look at HRS.com (Hotel Reservations Service) which I have been using for years. It has a lot of features including good prices, special offers, photos, distances to points of interest, etc. I live in Germany and have found it invaluable.
Sorry to be so tardy in answering you. Congratulations on booking a tour to the Passion Play. This is an extraordinary event taking place once every ten years. I am sure you will not be disappointed. As far as hotels are concerned I would suggest the Zugspitz Hotel in Garmisch-Partenkirchen. Here is the link. They have good packages with lots of extras thrown in, like bicycle rental, etc. http://www.hotel-zugspitze.de/english/index.php We book all our friends into that hotel.
Thanks everyone for the great suggestions. I'm looking forward to researching all the new ideas and finalizing our trip! Hopefully Germany will be nice and cool (or at least not Houston temperature 100 degrees plus humidity) this August.