I have only a week in a town outside Munich, called Garmisch. I will be staying at a military hotel that offers cheap tours ($50- 100). I'm in a toss up, should I drive to Salzburg and tour it myself( since the hotel doesn't offer a Salzburg tour) or should I go and see the Eagle's Nest(Hotel Tour)? Is the Eagle's Nest just for a view? If so,I'd rather do the parasailing ride my hotel has to offer. I read in Rick Steve Best of Europe 2011 that many of the sights in Salzburg were mediocre and it was more of pretty city of great architecture. On the other hand I had a close friend who visited many of the cities of central Europe tell me Salzburg was his favorite city.
In addition to the views, Eagle's Nest has some WWII history interest. If you are interested in WWII history, this might be a good option for you. I enjoy both Salzburg and Eagle's Nest, but between the two, I would choose Salzburg. Salzburg is one of my favorite European cities. It's easily walkable on your own. The old town has many beautiful squares and lanes you can wander through, and you can visit the fortress on your own.
I would choose Salzburg unless you are a huge WWII fan. Salzburg is very unique, small enough to easily walk in a day, and there is so much to see. You can also go to some of the neighboring villages in the surrounding alps to get a sense of what the area is like...they are some of the most beautiful little places I have ever been and are surrounded by STUNNING alpine mountains.
Ian, I really enjoy all the history of WWII and have been to the Eagles Nest but I have been to Salzburg 4 times and would not hesitate to go again. Great city to walk or even bike. Don't know what your interest are, but I never hear of anyone not enjoying Salzburg.
I don't really want to poke holes in your plans, but I think you should take a look at where these places are really located (use Google Earth) before making firm decisions. Garmisch-Partenkirchen is almost 200 km (125 mi) from Berchtesgaden (near the Obersalzberg). If the Obersalzberg is what you want to see, save the bus fare and stay in Berchtesgaden. I've stayed in the military hotels when both of these were Army Recreation Centers, and they were thoroughly unsatisfactory experiences (and I was in the Army!). You are much better off staying in a local German run/owned hotel/Gasthaus, both from a quality and service standpoint. Garmish-Partenkirchen has its own attractions. The parasailing sounds sounds good. Garmisch also has a funicular railway and cable-car trip to the top of the Zugspitze. The town itself is very pleasant & picturesque, and it's easier to get to than Berchtesgaden.
I've been to Salzburg four times. First was just for dinner, second a full day's sightseeing, last two just to change transportation (train-bus, train-train) at the Hbf. I've been to Berchtesgaden three times. In October, I'm going back to the area with a friend, who has never been to Europe. I will take her to Berchtesgaden, not Salzburg. 'Nough said? Not that Salzburg doesn't have interesting things to see, but I've seen them. I never get tired of the scenic beauty of Berchtesgaden. Hopefully, your Eagles Nest tour will cover more than just the Nest. The Dokumentation Center below it documents the Nazi raise to power and is well worth the time.
If your interest in the Eagle's Nest is its historical connection to Hitler, note that the well-known photos and films of him and his Nazi associates in front of a huge picture window or on a terrace with spectacular alpine views are NOT from the Eagle's Nest but from Hitler's private house in Obersalzberg. This is also where Goring and other top Nazis had their lodges, and where the complex of bunkers and interconnected tunnels are located. You might want to check this section of Third Reich In Ruins for further info: http://www.thirdreichruins.com/obersalzberg.htm
Can you wait until you are there to make a decision? I would choose Eagle's Nest and other Berchtesgaden sites (Konigsee, Jennerbahn) if the sky is clear. Low clouds ruin alpine views. If the weather tended toward rain or clouds I would choose Salzburg in a heartbeat.