In Germany you'll find i.e.:
- the Rheinsteig (320km, near the banks or on the hills of the Rhein valley, I recommend to walk from south to north, sometimes busy)
- the Rennsteig (170km through the rural Thuringian Forest, running from Eisenach to Blankenstein, very laid back like in the 70s / 80s, but with some problems in lodging-infrastructure)
- the Heidschnuckenweg (220km through the Lueneburger Heath from Hamburg to Celle, very flat, best from start of August to start of September, 08.08. to 09.09. they say, very busy in this time)
- the Hochrhoener (180km between Bavaria and Thuringia with quite a lot of mountaineous parts, best trekking-path of Germany in 2010)
- the Via Regia (470km from Görlitz to Vacha, it's an ecumenical pilgrimage, following an middle age trading route, only 60-70 accomodations and very quiet)
Hope I could give you some inspiration.
BC
Roland