Landstuhl: I don't know much about it, only that it is a major US military base with many US Armed Forced bases around it. Baumholder aka "The Rock" is probably the most famous of them.
Closest cities are Kaiserslautern and Saarbrücken, pubs there are usually full with US Armed Forces guys enjoying their leave and looking for (German) women and girls.
Nearby Saarbrücken used to be big in steel-manufacturing, now unemployment is relatively high. Not a very exciting area of Germany in general, a bit drab. Good thing are the good connections by rail, always a decent indicator in Germany that you aren't in a place that is completely dead.
Looking further on the map: Frankfurt-Mannheim is one of the bigger urban areas in Germany, all cities there are expensive places to live in. Curious mix of blue collar workers and very well-paid bankers. Frankfurt is nicknamed "Mainhattan" for its skyline and its similarity to NYC as a banking and finance place.
Most positive thing I have to say about the area is that it is not too far away from France and Belgium. Extended weekend trips to Paris and other French cities are most definitely possible. Catch the train from Saarbrücken, book in advance through www.bahn.de to get special offers.
The Rhine and Mosel Valley north of the Hunsrück mountains are great too, very popular with tourists. I would most definitely do a drive along the Mosel Valley and the Rhine Valley in October when the leaves turn.
And great cities to check out nearby are Karlsruhe, Trier and Heidelberg.
If you got relatives in the USA check out whether you can fly them in on USAF flights for a fraction of the price you'd pay with regular airlines.
EDIT: If you get a choice between Landstuhl and Baumholder, take Landstuhl! Baumholder is pretty much at the edge of the universe.
[ Edit: Edited on 08-Aug-2009, at 12:56 by t_maia ]