Despite the availability of a large number of tools based on the flickr photo sharing site, the only convenient tool I found for downloading all your flickr favorites is FlickrFaves (see attached screenshot). It's a small tool written in Java, which uses flickrj (a java-based wrapper library for the REST-based flickr API) for the single purpose of downloading someones flickr favorites. Furthermore, it's GPL licensed open source software and provides an interesting entry into the world of the flickr API.
It's use is completely straight forward: 1.) Start FlickrFaves 2.) Authorize the program with flickr 3.) Set the parameters 4.) Download your favorites.
Please note that FlickrFaves doesn't take care about any metadata. The downloaded photos will have cryptic filenames and won't have any information about the tags it was assigned to on flickr.