listed in no particular oder

Frank Miller: Batman slaps Superman around and retires. what else needs to be said
Dark Knight Returns
Year One, Day One

John Julius Norwich: basic overview of Byzantine history
Byzantium (3 volume set)
The Early Years
The Apogee
The Decline and Fall

Bernard Cornwell: great narratives from a author with a good grasp of history and anthropology. very rare indeed.
The Saxon Chronicles
The Grail Quest
Warlord Chronicles

Morgan Llywelyn: novelized versions of celtic myths.
Red Branch
Lion of Ireland
Pride of Lions
Finn Mac Cool

ROBERT E HOWARD: ohh the list is long, i like most things he wrote, I'll keep the list brief,
The Phoenix on the sword
http://www.gutenberg.net.au/ebooks06/0600811h.html
Red Nails
http://www.gutenberg.net.au/ebooks06/0600771h.html
Queen of the Black Coast
http://www.gutenberg.net.au/ebooks06/0600961h.html
The Frost Giants Daughter
http://www.gutenberg.net.au/ebooks06/0600751h.html

Christian Tobler: Tobler has done a tremendous amount of work researching and making accessible formally forgot european martial arts.

Fighting with the German Longsword

Secrets of German Medieval Swordsmanship: Sigmund Ringeck's Commentaries on Liechtenauer

In Service of the Duke (The 15th Century Fighting Treatise of Paulus Kal)

Marcus Aurelius: do i really need to say more
The Meditations
http://classics.mit.edu/Antoninus/meditations.html