Naruto is currently my third favorite anime of all time. Fairy Tail is ranked second, but if it doesn't proceed all the way to the ending of the manga, it will drop dramatically from its current optimistic scenario place. This means Naruto is likely to rise all the way up to #2 in the distant future. Why do I like Naruto so much?
#1: Excitement. Naruto is a battle manga par excellance. In fact, I would say it has the best battles of any series ever made. It combines the flashiness of Dragon Ball, the clever tactics of Hunter x Hunter, and the heartfelt feelings of Fairy Tail into one action-packed ball of pleasure. It may not be the maximum in any of these fields, but it has elements from every other good shonen series and achieves a more balanced whole.
#2: Rewatchability: No matter how many times you rewatch Naruto, it never gets old. There's something charming and lovable about the characters, the music, the famous scenes and statements, and the tour de force of the story that makes you want to come back and experience it over and over again. The only series more rewatchable than Naruto is One Piece. Dragon Ball and Fairy Tail are also good in these fields, but somehow Naruto is just more charming in hindsight, like well-aged curry. Or should that be wine? Either way.
#3: Continuity: Every episode of Naruto is tightly bound to every other episode of Naruto in a tightly bound web. In fact, there is no story that excels Naruto in this field. I am simply amazed at how closely connected everyone in the story is, and every event that happens to all the other events. Everyone is full of relationships with everyone else, there's no scene or person left dangling who exists without a purpose. This is just quite simply the best written, mechanically speaking, story ever. No wasted motions, no wasted space, nothing that drags or distracts the story from its central theme.
#4: Community: Naruto is a fantastic world in that the people have such a strong heritage and bonds with each other that it feels more real than real life. Everyone in Naruto can trace their nature and nurture back through multiple generations. The first and second taught the third Hokage. The third taught Jiraiya, who taught the 4th Hokage, who taught Kakashi, who taught the 4th's son Naruto. The entire history of the village flows directly into Naruto's life course. Everyone is affected, in a direct line of descent, by those who came before them. This sense of inheritance, of history being in motion, makes the world feel just as ancient and dynamic and living as the real world. In addition, the three students plus one teacher system creates tons of powerful bonds quickly and sensibly, making all the characters more interesting than if they'd been left alone.
#5: Characters: It's rare for me to even remember the names of characters in anime, even the shows I like. However, I remember virtually everyone's names in Naruto. That's because their art design, their relationships, their actions and way of speaking, are all memorable enough to get recorded somewhere in my brain. Sakura, Sasuke, Naruto, Ino, Shikamaru, Chouji, Shino, Kiba, Hinata, Neiji, Lee, Tenten, Gaara, Kankurou, Temari, Kin, Dosu, Zaku, Orochimaru, Jiraiya, Tsunade, Kabuto, Kimimaro, Konohamaru, Chiyo, Sasori, Itachi, Deidara, Kisame, Nagato, Yahiko, Konan, Zetsu, Obito, Madara, Kakashi, Gai, Kurenai, Asuma, Hidan, Kakuzu, Zabuza, Haku, Suigetsu, Karin, Rin, Jugo, B. . . I could go on and on. I probably know a 100 names from the Naruto series, all distinct, likable characters you can warm up to in a flash. The characters in Naruto tend to have a serious side and a comical side, which is the exact right balance everyone should have. In addition, they all love someone and are loved by someone, which makes them all bigger than just themselves. Ino taking care of Sakura is an unforgettable scene. And when Ino jumps in to help Sakura, Shikamaru and Chouji follow, because they're part of her team. In just this way the bonds keep radiating further and further outward, until everyone in the whole world seems to be connected. Like one giant shinobi family.
#6: Message: Naruto stays on theme, all the time. What is Naruto's theme? That there's an inseparable darkness to all light, but nevertheless it's all worth it because the light is just that good. For instance, Haku wanting to be with Zabuza even though it meant he would be forced to do evil for a living. Or Gaara becoming the Kazekage despite his own village trying to assassinate him. Or Naruto refusing to abandon Sasuke even though all he caused Naruto was trouble and Sakura was willing to go out with him if he did. Or not accepting the dream world of the Tsuki no Me. Or Shikamaru not quitting as a ninja just because his first mission had been a failure. There are endless opportunities in this series to chicken out and give up, but each and every time the characters rise to the occasion, no matter how difficult the challenge, because they have something that would hurt even more if they lost it instead -- honor, friendship, children, self-respect, curiosity, love -- it doesn't matter what. What's important is how hard everyone in Naruto tries and how much they're willing to sacrifice to see through their goals to the end.
The one thing Naruto lacks is emotion. There are a few tearjerking moments in Naruto. But compared to One Piece, Fairy Tail, Clannad, Little Busters, Pretty Cure and other top tier shows it's actually surprisingly thin on the ground. Naruto tends to stay positive and avoid really wrecking someone's emotional equilibrium. It is rarely uproariously funny either, so it can't be called a comedy either. It isn't a horror series, or something that makes you righteously wrathful about anything. It just sticks to the middle of the road and flows through its practical content. Naruto lives mainly in the brain and doesn't worry too much about the heart. This weakness really shows up when compared to One Piece, which specializes in making heart wrenching stories over and over again, about people we originally didn't even care about, the author makes us care and cry seemingly whenever he wants us too, he's just so good at getting us emotionally invested in the scene.
The biggest technical problem with Naruto is its heavy use of flashbacks just to draw out every episode in order to not catch up with the manga. The One Piece anime has this same problem, in that half of every episode is wasted solely in order to slow the pace down. There's no solution to this, because manga is always slower than anime, but it's still frustrating every time it happens.
If these two complaints are all I've got, though, Naruto may as well be perfect. Rarely does a show last this long while staying at the same equivalent quality throughout its entire length. If you paratroop down into any section of the story, and watch eight episodes in a row, you'll be just as hooked as if you had paratrooped down into any other eight episode segment. There simply is no bad arc. That's different from One Piece, Fairy Tail, or any other series of equivalent length. Naruto is just magic.