http://bibliodyssey.blogspot.com/
It has beautiful and esotiric prints and images from old books. Look in the archives. That blog has been actively updated for many years. There is some really cool stuff in the history.
I keep it in my bookmarks and just look at it every month or so. Some things are bizare and strange, some are mundane like "patterns of wallpaper for your 1800's mansion" and so on.
Diaper comes from the Greek words meaning "diamond" or "diagonal" and "white". Diapering is a term used in architecture as well; it's not meant to be a comparison to a nappy.
Also very few people will read the original, and will go with modern english translations, donno if you'd consider that cheating. And I'm guessing you're limiting to western europe because thats what the linked story did.
Beowulf is just cool. Here's a thousand year old D+D campaign waiting to be played. I'm sure someone has RPG'd it up in the last 40 years or so.
The Sagas are interesting, same argument see above.
Nibelungenlied is kinda cool. Ditto as above.
The divine comedy is just weird. Maybe you could make a MUD/MUSH out of it or an artists interpretation in Minecraft for Halloween.
You can troll people with Petrarch, many say he's the first Renaissance dude so he doesn't count. Well, just don't tell those people, then they can't harass you. If you really want to piss them off try "ah, plutarch, petrarch, whats the difference anyway". (Plutarch is Awesome to read but he's about 400 years too old for your cutoff) Anyway his mountain climbing story will be the weirdest travelogue you'll ever read, and some people find "weird" to be aesthetically appealing. There are English translations on the net for free. See something "weird" like fear and loathing in las vegas can be explained away by drug use, but petrarch's story has no excuse making it weirder.
I remember Sainte-Augustine by his quote "Grant me chastity and continence, but not yet" and it would be interesting to see how a hedonistic turned into one of the most famous and revered characters of the Church. Dante's Divine Comedy tells about the scholastic tradition and how the leading thinkers were introducing pagan thought into their discourses. Petrarch book shows the start of the Renaissance and how current human thought can add to secular knowledge.
http://www.exurbe.com/?p=2176 gets into some of this in discussing a couple of TV series set in the Renaissance: one of them's pushed more into a modern story-shape that modern viewers expect. (Skip down to the two paragraphs on Episode 1.)
Confessions of St. Augustine is from late antiquity but I think should "count" as medieval because it was so influential to scholasticism, and is similarly great/relatable.
The Travels of both Marco Polo and Ibn Battutah (rough contemporaries who were active toward the end of the medieval period in the fourteenth century) are both fascinating and entertaining tours of the Mediterranean, Middle East and Asia.
I hope it doesn't scream when I open it? :-)