The Frankenweg is well-known among hikers in Germany, so I find it odd that I can't find any speed records for the entire 520 km trail. Now, this could just be my dodgy German skills or the fact that 520 km (About 320 miles) is a nasty distance for speed.
Either way, I feel like it deserves to be on here. It's well known, has a definitive route (the GPX file is from the official Frankenweg website), and there are multiple options for completing it in different FKT styles.
As to the route, it has a surprising amount of variation, moving from forests to hills, crazy rock formations, rolling fields, ancient buildings and even more ancient ruins. Not that you'll have time to enjoy those all that much!