Although the movie trilogy skips some interesting backstories, muddles a few others, it also skips weak humorous attempts and other plot nonsense that was introduced in the show, purely to fill time, disavowing the entire show's tone in the process. The movies condense quite a lot to fit the format's length, but the superior serious tone, the polished graphics and animation, and above all a proper ending, justify the trilogy over the 1997 show any time.

A lot of people have praised the manga, which is usually the case for any good anime; my guess is that its fine. But the movies are way better than the tv series. I understand that the slower pace and better context given by the series is good, the movies do feel rushed in their storytelling, but I didn't find it that big of a deal considering that the movies do a good enough job of retelling the original series story. Besides, one can't be expected to invest 12 hours of their time into a show like Berserk and have that revolting ending (or lack thereof).