-Diverse-

Tourendatenbank
New interactive portal with hundreds of valuable tour suggestions from all over Europe
GPS-Tracks.com
Many tours but for the part that is subject to a charge. Especially in the Alpine region.
Trailino.com
Upload and create tours that will appear with additional information.
GPSies.com
Tours site based on Google maps (display and creation of tracks). Focus on Germany.
Giscover
Large collection of tours with a focus on Italy
GPS-Tour.info
Very large collection of tours.

Austria

TyrolKitz Touren - das Tourenportal der Kitzbüheler Alpen
Over 200 tours in different kinds of sports are available.

France

-Diverse-TraceGps
More than 1500 tracks in France and Europe
-Diverse-bivouak.net
Emphasis in the area Rhône Alpes'

Germany

BavariaGPS Tourdatenbank im Bayerischen Drei Laender Eck
GPS Tours database for mountain biking, cycling, hiking and snowshoe tours in the Bavarian Forest, Germany, Austria and the Czech Republic with tour descriptions and free GPX data to download.
BavariaDer Rhönführer
Here is a database of POI and GPS - tours for the Rhön.

Switzerland

-Diverse-GPS-Touren.ch
Especially Graubünden/Eastern Switzerland