It's hard to review this manga precisely since, in my opinion, it's full of ups and downs.

Since I am reviewing the manga, I will not get into the terrible anime issues (mostly it's pacing problems with long staring scenes mid-fight and tons of flashbacks).

SPOILER ALERT: Tons of spoiler ahead, don't read it if you have not finished, except if you don't mind spoilers.

Naruto starts as a very good and promising story, with potentially interesting and likable characters, and also with lots of potential for good action scenes. However, over time, most of it (if not all) fall to pieces.

Before the time-skip it actually manages to keep quite a high quality in general. The best arcs are for sure in this first part of the story with the Chunin exam, the badass introduction of Orochimaru, the introduction of Itachi, the rivalry between Naruto and Sasuke (that at this point it was actually appealing), and even some nice lessons it was trying to teach, such as the value of effort - with even a quite remarkable scene between Naruto and Neiji at the end of the Chunin exam.

It was also in the first part that some of the most interesting, fantastic and skilled side characters are presented, such as Rock Lee, Gaara, Kakashi and Jiraya.

The biggest problem with the 1st part is, probably, how Sakura is constantly portrayed as weak, with a very boring and embarrassing unrequited romance with Sasuke, and with an equally embarrassing rivalry with Ino. It was a wasted potential of what could have been a great female lead.

However, I could for sure say that the first part of Naruto manga is solid, good, and held great potential.

It falls apart however in the second part, after the time-skip (Naruto Shippuden in the anime).

The second part of Naruto starts pretty bad already, showing a "grown" Naruto. Grown only in size however, since you immedialty notice that he still maintains the exact same attitude and immature behavior as he was a kid.

It then introduces a new plot which Gaara is quite easily captured by some of the weakest Akatsuki members (Deidara) and is held captive until they extract from him his Biju, Shukaku. It then explains that the Akatsuki wants to extract all Biju to hold an ultimate weapon. What for? Well, I don't remember it ever being given a clear explanation, but it seems basically that they wanted "peace" through keeping the villages at war.

Actually, the whole Akatsuki premise falls apart pretty fast, when you realize that apparently most of it's own members doesn't have a clue of what they're fighting for.

When the Akatsuki members fail to capture the Eight Tails (Killer B) and the Nine Tails (Naruto), Tobi (one of it's members) reveals himself as Madara and declares to the leaders of the Ninja Villages he wants to put everyone under an eternal state of sleep in which they would be living happy dreams, if they hand him, deliberately, the remaining Jinchuriki. Since the leaders, obviously, deny it, Tobi / Madara declares a Ninja War (basically a War with all the Ninjas in the world against a few remaining super overpowered akatsuki members).

At this point you realize that the plot is losing all its substance, and getting into a unnecessarily complex chain of events that hardly makes any sense.

Also at this point Naruto is fast evolving from a pretty ordinary (although pretty strong too) shinobi to a one of the strongest beings in the lore after undergoing multiple transformations and overpowering his basically only two ever learned skills: rasengan and shadow clone jutsu. This progress, however, happens way too fast, as it's easily noticiable that his skills are, apparently, surpassing the ones we saw in the first part by some of the strongest characters such as Orochimaru, Jiraya and even the 3rd Hokage Sarutobi.

This is when you realize that the series has gone to a DBZ route of power progression, where each new enemy appears to be the new strongest being ever using skills that are far superior than pretty much anything shown before, making Gaara and Rock Lee, for example, look like a joke.

When the Ninja War starts Kabuto appears with a snake-like skin, helping the Akatsuki and using an improved Edo Tensei, the same skill Orochimaru used to fight against Sarutobi in the 1st part, except that here it used to ressurrect, with no costs at all, pretty much every single legendary ninja that ever existed in the lore. It's also said that his now enslaved ressurrected ninjas have infinity chakra, can't die again (recquiring to be sealed instead), and feels no pain - they can, however, think, strategize and fight coordinately as a group.

Kishimoto (Naruto's author) obviously couldn't come with any other solution to defeat such a threat, other than shieldening the "good" characters with plot nonsenses and making many of them suddenly overpowered too.

After some events that reveals that Tobi is actually an old Kakashi friend that has been actually sided to Madara, the real Madara is revealed as an Edo Tensei brought back to life by Kabuto. Also, out of thin air plot wise, Madara reveals he can actually free himself of the Edo Tensei spell, and become an completely autonomous being that can't die, feel pain or lose chakra. At this point I really wasn't being able to take the plot seriously anymore.

Madara and Tobi releases the Ten Tails Biju, which attacks everyone with HUGE blasts of very destructive powers, but Naruto, suddenly, realizes he can shield everyone transfering as a body armor his own chakra to EVERY SINGLE ninja in the battlefield borrowing an almost infinity amount of it from Kurama (Nine Tails). This is just one more example that Naruto powers has already gone through the roof - and unbelievably, it gets much worse.

At some point, after taking a detour to know himself (usuless by the way, cause it changes absolutely nothing about him) Sasuke comes to the battlefield to help Naruto. And after tons of panels of stupidly huge powers here and there and tons of drama regarding Tobi, Madara becomes the Ten Tail Jinchuriki acquiring god-like powers.

Once more, since there was absolutely no chance for Naruto and Sasuke to be this strong yet (if ever), Kushimoto comes with a great idea: they're both basically summoned by the Sage of Six Paths, that reveals them they're LITERALLY the descendants of the Gods Asura and Indra, giving them the power of Ying Yang. Yeah, for real!!!

Here is when the basic premise of the whole 1st part falls apart. Neiji was right all along when he confronted Naruto in the Chunin exam saying that talent and abilities were pre-determined at birth, and that the destiny was basically set from the time someone is born. Indeed, that's EXACTLY what the end of the series teaches: Naruto only ever gets so strong because 1) he was Nine Tails Jinchuriki and 2) he was a descendant of a God. Poor Neiji... had his mind changed by Naruto and gets killed before realizing how right he was.

Madara, then, gets betrayed by the Black Zetsu (one of the Akatsuki members) which stabs him in the back basically killing him and bringing a being called Kaguya back to life. Black Zetsu is revealed to be some sort of Kaguya's evil will. And is also revealed that Kaguya was the Sage of Six Path mother and basically the creator of all Chakra. None of this was ever hinted before!

So in order to defeat such a powerful being, Naruto and Sasuke fight alongside and uses their Ying-Yang power to save the world. Yeah, Naruto and Sasuke ended up literally surpassing a Goddess.

After all this, Sasuke reveals he hasn't changed his mind at all up until this point, and is ready to kill Naruto so then he could kill every single village leader with and accomplish some nonsense about "bearing all the pain in the world". They fight, they almost die, and Sasuke finally comes back to his senses and becomes "good" again, recognizing Naruto as friend, and gets forgiven by everyone.

That being said, the main thing the 2nd part of Naruto manages is to ignore EVERYTHING was built in the 1st part. Interesting and skilled characters simply had no room to shiny anymore. The whole effort premise was thrown in the trash. Everything was about Naruto becoming extremely overpowered after each training section and receiving an exceedingly amount of powers from Kurama and Hagoromo.

Also, the three main characters ended up such a disappointment: Naruto talks gets really tiresome after a while with that whole "I will become a Hokage" and "that's my Ninja Way". Equally tiresome was Sasuke's stubbornness about a supposedly "revolution" in which he intended to "bear all the pain" by himself intending to kill every village leader. And Sakura only ever shines once, in her fight against Sasori - and even then, I particularly think that fight was quite boring anyway.

That being said, Naruto had tons of potential and actually managed to deliver lots of good moments before the time-skip. After it though it just keeps getting worse and worse, with the whole Ninja War arc being everything it should have NOT.