Recently, a friend advised me to watch this series without knowing that it had a manga associated with it. The anime in and of itself was interesting and dramatic but like any good anime, left you hungry for more after it ended.
The manga has the two main qualities that I need in the fiction is immerse myself in:
I read chapters 1 to 300 within 3 days. Berserk prevents itself from falling into a repetitive pattern of Monster/Villain-of-the-week fights. In fact, in close to 316 chapters, the protagonist, Guts, has had perhaps 6 or 7 major fights. What I really appreciated about this series was how it took the time to build up its villains, giving many of them elaborate back-stories and actual lives outside villainy. While the back-stories don't really make them more sympathetic, it does make the battles more memorable. Up until the 250th chapter or so, the plot maintain great pace, with a steady stream of characterization, world building and plot advancement. However, I feel that some of that momentum was lost at around this point and what I really like about these characters (their cold-bloodness, their anger/hatred) was lost and replaced with a (relative) candy coating.
The series can really fall under different genres at different points in time - at the beginning, it was generally a dark fantasy manga. Then for 10 volumes it read almost like a historical battle/war manga with some hints of romance. Since then its back to dark fantasy and action. Worth a read for sure, but not for the sensitive.