I liked him in the begining when he was an underdog! Dead last, but learned a complex Jutsu in mere hours and defeated a Chunin with it. Loved when he would use Kurama chakra, back when Kurama was evil, that was beast. Pretty great up until he got all up in Sasuke's business, though. Shippuden was alright, but what he learned felt lacklustre, and, as Sasuke stated; maybe if he wasn't so focused on him, he could have improved more?
SM may have been his peak for me, or, one of. It was badass! The entrance, his seriousness; no bullshit there.
War arc was pretty good, wish Kishi didn't use his moments of idiocy as comic relief. I feel that it really wears on his character. Like, what happened to the development that his character did during the Pein Invasion? He didn't miss a beat then, didn't forget anything, not the intel IIRC. But, he like forgot some of Nagato's moves when he was battling him, like, really..? :| That's just a single example too.
BM was another pretty badass moment, same with BSM, and RSM. But, when Sasuke got there (to the war), he felt a bit too focused on him.. :hmm:
Thing that made me think less of Naruto was the Obito wank. No matter which way you slice it, I cannot find it acceptable.
Overall, Naruto's still pretty good, probably tied for second with Kakashi as my "Faves" on Team 7 list, Sasuke being first, since the Obito thing, and Sakura last.
Edit: Yeah, it was commendable that he never gave up, even when the odds are stacked against him. But, I think sometimes that "never giving up" is brought up too much in the series, but w/e.