Berserk

From ANN:

Guts, known as the Black Swordsman, seeks sanctuary from the demonic forces attracted to him and his woman because of a demonic mark on their necks, and also vengeance against the man who branded him as an unholy sacrifice. Aided only by his titanic strength gained from a harsh childhood lived with mercenaries, a gigantic sword, and an iron prosthetic left hand, Guts must struggle against his bleak destiny, all the while fighting with a rage that might strip him of his humanity.

Warning: This manga is for mature audiences only, since it has sexual content and graphic violence (gore, blood, rape, etc). Definitely not for the weak hearted.

The 1988 Prototype chapter won a prize at the Comi Manga School Miura attended and the main series won the Tezuka Osamu Award for Excellence in 2002.