Naruto is a story I have terribly mixed feelings about, especially since I devoted a lot of time in the past to writing fanfiction for it... back when I still liked the series.
The most addicting thing about Naruto is the "Naruverse." There is just so much potential in the Naruto world. You have ninja magic that covers a BROAD spectrum of abilities, you have a few deviants in Konoha (Naruto's home town), you have "missing-nin" who betrayed Konoha (most notably men by the names of Orochimaru and Uchiha Itachi), you have demon magic, you have enemy nations who are not on good terms with Konoha, and you have an evil organization bent on world domination.
Wow. Kishimoto spared no expense in setting up a world that would give him virtually unlimited storytelling options. There ARE some inconsistencies, specifically revolving around technology, but aside from that, you can easily get addicted to the Naruverse.
The problems arise in the storytelling. Naruto can be divided into two parts, each I will give thought into separately.
Part 1 of Naruto sets the stage in a very typical shounen way, with the difference that he is hated because of a demon sealed inside of him that everyone fears. He has a rival, an emotionally disturbed kid whose entire clan was massacred by his elder brother (the aforementioned Uchiha Itachi killed them all). They go through trialsand tribulations and appear to change and grow. Naruto starts growing up from the kid he once was and starts becoming a powerful ninja, while Sasuke is faced with choices regarding his revenge and his friendship.
Part 2 is where the story totally breaks down. Kishimoto throws all the character development out the window and changes characters into what he wants them to be at this point using a a 3 year time jump as the excuse. Character personalities in some characters have completely reverted back and in other characters seem different in ways that don't make sense. For reasons I cannot tell, the story stops focusing on developing characters and starts hyping them instead. We're TOLD that technique X or ability Y is super powerful and nobody can perform it except character Z and nobody can stop it no matter who they are. In this way, "S-class" ninjas are given an "S-class" shield by Kishimoto, which is only broken down by convenient plot devices that destroy characterization.
Rating: 4/10.
I'm fine with the cliche shounen elements so long as the storytelling is good enough. Part 1's storytelling was enough to keep me from bemoaning the problems with the series. Part 2 lost it.