Short-term plotting (grabbing my interest)
From the beginning, we have a main character who has a short-term goal: be allowed to take the Hunter exam, pass the Hunter exam, and get a Hunter license. He meets other people with the same short-term goal. Action, mayhem, and brutality ensue. I am invested in this short-term goal and am willing to stick with the manga long enough to see it through.
Long-term plotting (character development in trickles, getting me more invested in what might happen after the short-term goal is accomplished)
We meet each character and slowly get to know more about what makes them tick (in Hisoka's case, I'm guessing blood made of evil). Our first impressions are changed as we spend time with people under pressure, and the relationships get a little deeper as people get more invested in each other's success. So Leorio likes money and wants to be a doctor; why? Kurapika wants impossible revenge. How? Killua was raised by assassins, but he kind of wants to try hanging out like a normal kid and having fun and making a friend and stuff and maybe kind of redeeming his soul even if he doesn't think about it like that because he's twelve. Gon's dad? Keep reading. Killua's family? Yeah, keep going. Finding out what it means to really be a Hunter? Yep, the exam isn't over yet.
Close adherence to source material
Countless times, there is a great manga, and then they make it into an anime, and you watch it and don't like it because things you liked from the manga seem to be missing for no discernable reason, replaced by repetitive romantic comedy or pointless quests or five minute fights that last five hours. Not so in HxH. It's actually kind of scary how closely they adhere to the source material. I don't understand why people don't do it more often. I mean, the dialogue is already written, the fight is already choreographed. People liked it a lot. Use the stuff! What a great way to cut corners without ticking off viewers or the creator.
Decent original material
Wow. It was a shocker to me, but, in the second collection Viz put out, there was another round added to the Hunter exam, and it was pretty good. Not only were several characters given a bit more time to develop, but the group dynamic really grew (which made the part where they resumed the original story line and killed off a bunch of the people even more harsh). And two very unexpected people saved the day in a really natural way. If I hadn't known it was an anime-original arc, I wouldn't have known; it was that organic. See, it can happen.
No crappy moral of the story inserted for the edification of younger viewers
We do learn about how friendship can be a good thing, but it's in the context of a lot of fighting to the death. Yep, brutality, sometimes ambiguous motives and morals, murder, violence, more violence, and some stuff about friendship and trust and self-discovery and stuff. I mean, even if your friend up and kills someone for no really good reason, that doesn't mean you should give up on the poor, little sociopath. He really was manipulated/provoked, and you shouldn't hold it against him. That's kind of the moral of the story where it left off with collection II. There's so much violence, but what upsets Gon the most is that the sociopath in question's brother took him apart psychologically and reduced him to the killer he was trying so hard not to be and then didn't even feel bad about it. Definitely not After-School Special territory.
Of course, I'm invested in this show from my manga reading, and I really hope it sells well enough that we at least get to see through the Auction and Greed Island (and maybe even, you know, until Gon and his dad meet up), so I may not be completely objective (hahaha), but I really get a kick out of this creation in both forms and hope that more people check it out and enjoy it like I do.
Don't fear the old school; love the old school. Some day, the stuff you love will also seem horribly outdated and aesthetically awful and will need love, too. Appreciating older stuff now is kind of like paying the love forward. Or something.
Is there an older anime/manga you really wish people appreciated as much as you do? Give it a little hug by sharing it with us, please.