Plot/Story
Berserk first starts with Guts, a dark and indescribably strong swordsman, killing of some monster terrorising a town. However he is not some nice hero, since he doesn't give shit who he kills along the way. But this is the past, so the story really starts at the end of the 3rd volume where the young guts meets a band of mercendaries led by the charismatic Griffith, the band of the hawks. So a story of war, destiny, friendship, betrayal, love and hate begins. The whole story is set in a dark fantasy world, somewhat resembling medieval europe. The dark feel and atmosphere is underlined by very strong violence, gore and less nudity. All characters undergo excessive development and there are major twists making this story one of the most interesting stories I could even imagine (well it's my favorite..)
Characters
Guts: Incredibly strong swordsman born from a corpse hanging on a tree and then adopted by an insane wife of a mercendary. Lived his whole life on the battlefield and wields an incredibly large sword.

Griffith: Leader of the band of the hawk. Extremly clever tactition with the ambition to take a country. Does everything neccesary to achieve his goals. He is the reason the hawks are undefeated in battle.

Casca: Griffith's right hand. She is the only woman with the hawks and their strongest fighter besides Griffith (and Guts after he is forced to join). To her Griffiths word is law and if he orders her to kill a comrade, she will do it without asking questions.
Drawing Style
Genuine. The characters and the background are very realistic and detailed. Many pictures are pieces of real art. There are few mangas that impress with such astonishing artwork. It is clearly drawn and expresses every little aspect of the berserk world fittingly, therefore supports the atmosphere perfectly.
Enjoyment
Awesome. Once you get caught by this whole world, you won't be able to stop reading. After reading a while you start to believe to know the characters as if they are your friends. There is a great mix of breathtaking fights, secretely carried out plots, where all parties strive to be or remain in power or to come to power and some funny occurances. However it is no story for people who mind violence and gore. I wouldn't recommend it to be read by underage persons.
Overall
Overall a great story with really deep characters all assembled in a believable dark fantasy world. Drawn with incredible skill in a medieval setting. Crazy twists and great character development sum up to one great work.