He had no choice tho

Beside Naruto(Who is the MC so his development is not surprising) , i really liked Nagato's development. It started nicely, him becoming an orphan and being found by Jiraiya, who then realized that Nagato might be the child of prophecy who posses the sage's eyes.Then there was the stuff with the original akatsuki and Yahiko's death and Nagato accepting his rinnegan powers and becoming Pain.Afterwards he assumes his powers for his new idea of peace, starts the new akatsuki and kills his former master, then finally he is defeated by his sibling student and his former idea of peace is restored.He truly is a great character and made the introduction of the rinnegan something special.

Worst is by far Sakura. I mean yeah she got physically stronger in the ninjutsu and tajutsu department but as a character she was mind-numbly awful.

Anko is a good one, off the strength of being Orochimaru's disciple it just sounds amazing. Kishi made her a pawn then trolled her ass which was so dumb. Have to chalk it up that dude just doesn't know how to write women at all.

Worst - 1010. someone said rock lee, but at least my dude got a fight, and showed some type of growth. 1010 comes on screen, gets rekt off screen, says she wants to be like tsunade(which i don't even remember if it's canon or not, then....disappears. absolutely nothing. Then there's some others such as kurenai who was used as only fodder + baby maker, Anko, Kiba, just all wasted.

Best - Gaara had pretty good development from once we learn about him to PTS to the war, as did choji and shikamaru, can't really decide which one as of right now but leaning towards Gaara.

I understand that, but it doesn't really change what he did and it doesn't justify all those 'oh he was a hero' reactions. Itachi was an extreme case of Jiraiya's tragic story, except we actually saw Jiraiya acknowledge his mistakes while the only mistake that Itachi was given shit for was not telling Sasuke why he had murdered his own clan and that just casually plopped during a convo. with Naruto.

Then all that followed by Sasuke completely missing the point and suddenly adoring his older brother even THOUGH his brother still killed his clan. That did not change. It just seemed stupid to me.

Have to disagree about Hinata, shikamaru being just extras. Naruto definitely a best in my book. You thought on Sakura, Mr.Grave?

worst:pretty much everyone that wasn't an uchiha or naruto.

best:Naruto and Sasuke.

Sasuke had always cared deeply for Itachi. Even in Part 1, Itachi was his whole world. He lived to kill Itachi. Except he never really killed Itachi directly. Then Obito told him half-truths, which made the Uchiha (pride of Konoha) the buttmonkey of a bad joke. It's clear that the Uchiha clan are extremely prideful, hence why Sasuke took that so badly.

Furthermore, Sasuke's original mission only kept expanding. He killed Itachi to avenge the clan, but because Itachi died willingly, to avenge the clan he needs to kill those that gave that mission and ultimately, those who did nothing to stop it.

Sasuke never really stopped being that murder-intent kid from Part 1, as Orochimaru and Obito prevented Sasuke's natural healing from his mental scars. Every time there was progress, there was meddling.

I think Gaara actually shows the most character growth. He went from sociopath to a very loving and kind person. I feel he changed the most from Naruto to Shipudden with everyone else staying pretty much the same personality wise.

As for worst....Anyone who wasn't Naruto or an Uchiha in some shape form or fashion got the shaft in screen time and plot relevance. I love Hinata, but really she got more screen time then most, but was essentially the same throughout the series. Sakura is also very bad since as soon as she got a powerup so she could play with the big ninja, the big ninja upped their game and left her behind. She also stayed the same personality wise and was crying out for Sasuke as much as Hinata was crying out for Naruto.

The apex of Gaara's development was his war speech. Shit was epic and made me proud of a fictional character.