If ever any country takes pride in its romantic legacy, it must be Germany. Put on your hiking boots and headphones and enter the realm of Wagner, Brahms and Schumann, walking through the land of Rhine and Danube, of traditional half-timbered houses, mighty castles and ancient taverns serving excellent food and wine. Most popular hiking destinations are the Black Forest in the southwest, Alsace-Lorraine on the border with France, Bavaria in the south, and forested Thüringen and Harz in central Germany. But there is more to explore. Try an autumn clad Swabian Alb for instance, or spring on the northern island of Rügen.
Not surprisingly, Germany counts over 200 long distance hiking trails, all waymarked and well documented. Walk any European long distance trail, except E2 and E7, and you will pass through Germany! Even if not spectacular in terms of altitude, the varying landscapes can be truly wild and offer wonderful panorama's.
On the negative side, bear in mind that Germany is a modern country. Forests and farmland are exploited efficiently and can be pretty boring.
There are no real difficulties and you can go any time of the year, but higher up snow can make walking difficult in wintertime (and create good opportunities for cross country skiing). Finding food and lodging is never an issue, as mountain huts, hotels, inns and private rooms (Zimmer frei) abound, as do campsites.
Interesting is the current tendency in the country to "certify" trails if they comply to a list of standards. The effect is that some trails get much more attention than other trails. They get the predicate "Premiumweg" or get elected the most beautiful trail of the country. Of course, this does NOT mean that other trails are less interesting. The effect, however, is that while new trails are created, old trails gradually disappear.