The story is very unique, especially considering the times this series came out in with loads of generic action/comedy shounen series popping out every couple months. It's decidedly dark, serious and mysterious tone immediately draws the viewer into the story.
Probably the best part of the story is the characters and the interactions between them. It's a very character driven narrative and with the way that each character develops as the story progresses, it really shines. The exchanges between the main protagonist Light and his rival L are tense and never disappoint. Probably one of the best, if not the best, rivalry I've ever seen in an anime/manga (and I've seen a lot).
Everything else about the story is above-average.
Now, I would give Death Note a 10 overall, but there was one big flaw that I have to mention. I won't give anything away, but about halfway through the series there's a rather big change to the character roster. If the series had ended there, it would have had a pretty dark ending, but it would have been a satisfying conclusion in my opinion. Instead we are given a few new characters and the whole thing starts over almost from square one. Plus these new characters really pale in comparison to those that are lost soon before. This essentially splits the series in two with an excellent first half and a less than average second half.
I think it's a real shame that the author took the story in this direction, which seemed really forced to me. Plus it seemed to me that he only did this to make for a "good guys win" kind of ending, which also seemed really forced.
I know I'm going on about this, but compared to the first half of the series, the second half was crap. Even the intro/outro music was crap. Overall, an excellent anime/manga with a disappointing ending.
