The first thing I'll address are the elements of Hunter x Hunter that, whilst not bad, are certainly what I'd consider the most average things about the show, the visuals and the music. The visuals, whilst not bad by any means, are probably just slightly above average. The general visuals in this show never really rise anything above that. However, I'm willing to let the show slide on this element because out of the 148 episodes, the visual quality never slips and is maintained throughout the rather long run of the show. This itself is actually rather impressive considering there are 2 cour shows with inconsistent animation quality (See episode 4 of Gurren Laggan) so I'm willing to accept above average. The music is catchy and some of the songs are kind of memorable but they use a handful of songs and loops way too much and after 148 episodes it can be a little tired. Again, due to the length of the show, I'm willing to excuse that. It would be crazy to want new songs so often in a show of such length, but still, I noticed it and it bugged me a little.
The characters in this show are plentiful. I'm not sure if this similar in other Shounen but there are probably over 100 characters in total in this show. Granted, most of the characters of contained within certain arcs so it prevents the show from feeling overstuffed. These side characters all vary a lot and in the brief amount of screentime some of them get manage to make themselves memorable. Characters such as Bisky, Kite, Knuckle, Shoot, Palm and a ton of others are all very memorable despite them being in a small amount of episodes in some cases. As for the main characters, this show only really has 2 characters that consistently appear in every arc and, as such, are the main characters of the show. The 2 characters are quite well developed throughout the show, Killua more than Gon. Killua is the only one out of the pair that really goes through an arc, whereas Gon is more or less the same at the end as he is at the beginning in terms of personality. The character development is quite slow and gradual as you might expect with a show bordering on 150 episodes so the development feels very natural. A huge highlight of the show is chemistry between Gon and Killua and watching their relationship grow throughout the show. Gon and Killua don't know each other before the events of the show so you see their relationship start from the beginning on screen and watch it slowly develop throughout the series and by the end you get a genuine sense of how much of a bond the pair have formed during the show. It's probably on the same level, if not a little better than Fullmetal Alchemist in this area, it really is a delight to watch.
Now, onto the story. This show doesn't have a consistent storyline. Well, it kind of does. Gon trying to locate his father is present in most of the arcs and is sometimes the driving motivation however it is mostly a B plot, always something lingering in the background. So, since the story of this show is broken up into arcs, I shall break this particular section of the review into sections based on the various arcs, in chronological order.
Hunter Exam Arc:I think this arc is the closest this show really comes to being a traditional shounen show. I also think this arc is one of the best in the show. The amount of variety seen in this arc is great as Gon, Killua, Leorio and Kurapika participate in a series of tests in order to get their Hunter's License. All of these different tests are unique and are a lot of fun to watch. Some of the tests run a little long in terms of episodes but never enough to make you bored. This arc also does a good job of introducing the main cast of the show and establishing the world of the show. This is probably also the lightest the show goes in terms of tone. I'll touch more on this in later arcs but this show is a little all over the place with it's tone. This initial arc sets the show up to be this very light hearted show, which it really isn't. It isn't Madoka-esque but it can be a little jarring.
This arc is the worst arc in the show, not because it's bad but because it isn't long enough to do anything meaningful and is the only arc where, if it was taken out, I don't think it would impact the show much at all. All it really does is serve to establish Killua's family who are very important in a bunch of the later arcs. Other than that, this arc is probably one of the series lowest points. However, it is still entertaining and not bad by any stretch of the imagination.
Heavens Arena Arc:
This arc is more akin to JoJo's Bizarre Adventure. This arc is essentially the first training arc of the show and a lot of the episodes are dedicated to showing this. During this time, the show introduces the concept of Nen, a vague kind of power that is essentially the lynch pin of the rest of the show, and I'd say is quite comparable to Stands. It essentially serves as a means to give characters a bunch of creative and ludicrous fighting powers and I'm really glad they were introduced. Since the show gets more action heavy from here on in, these powers really stop the show from getting boring. As well as the Nen training, this arc also features a lot of fighting in the arena. This part of this arc is also comparable to JoJo as a lot of the fights don't boil down to who is strongest and is mostly about tactics and using abilities to get the upper hand. This makes the fights very entertaining to watch and are the highlights of this arc.
YorkNew City Arc:
YorkNew City, along with a later arc, is, for me, tied for the best arc in the show. This arc is when the show very abruptly becomes quite dark. Not the darkest it gets, but the show definitely feels very different in tone. This arc introduces the Phantom Troupe, a group briefly mentioned in previous arcs, a group of villains that are some of the best characters in the show. Each of them are very memorable and, despite them doing bad things, are still mostly quite likable. This show is quite good with giving it's villains shades of grey and this really enhances how entertaining the show is and how interesting the characters are. This arc also serves to give major and well needed character development to Kurapika who serves as this arc's main protagonist, and actually has quite little of Gon and Killua and this is the only time this really happens. Nen is used to great effect and, for me, was the visual peak of the show too. I did say earlier that the animation is consistent but I think this arc just looks a tiny bit better than the rest for me. Not exactly sure why.
Greed Island Arc:
Greed Island serves as kind of a calm before the storm in terms of it's placement in the arcs. I takes place right in between the two darkest points in the show and this kind of gives you tonal whiplash both ways going both in and out of the arc. I also find this arc to be the second weakest. It is another training arc but it is kind of dull to watch. This is redeemed slightly by the character of Bisky, who is the first female protagonist in the show and is a delight to watch and very cute. Aside from that, the villain is very 2 dimensional and since it takes place in a video game, it kind of takes the stakes out of it a little big, especially when there is a power in this game that can heal any wound. Again, not terrible or even bad but in comparison to the rest of the show, it is another low point.
Chimera Ant Arc:
This arc is probably the best of the bunch, along with YorkNew City. This is the peak of the show. It is also the longest arc of the show by far, so it has the most time to build up the story and characters of the arc and it really shows. Chimera Ant takes up two thirds of the show and uses it's time well. The story is a slow build and it introduces a lot of characters and almost all of them are well developed. This is by far the darkest the show gets and, without spoilers, can very very shocking and violent. It's not Hellsing Ultimate or anything but it can be quite shocking in contrast to the rest of series. The assault on the palace towards the end is very peak of the show and is just overall fantastic.
13th Hunter Chairman Election Arc:
The last arc of the show is quite disappointing. Well, half of it anyway. The election itself is boring and I didn't feel any interest in seeing who gets elected. That being said, the story with Killua is very good and entertaining, it's just bogged down by the other half of the arc that I really think wasn't needed. This arc also brings the anime to a close. Due to the manga being on going, there are a lot of loose threads by the end of the show but I think that it wraps up at a good spot and it feels like a natural end to the show. That being said, I do hope the rest of the Manga is adapted when it wraps up in however many years.
To sum up, I think Hunter x Hunter is a fantastic show, in some places it's downright superb. However, it is quite inconsistent in both tone and the quality of the arcs. None of the arcs are straight up bad, but some of them feel like they could have been better. I'd still recommend this show to just about anyone who isn't put off by the hefty episode count. I think it is a little bit overhyped but is still well worth a watch, just for the Yorknew City and Chimera Ant arcs alone.