Now, as the title/summary suggests, I loved this. It was the second anime I have ever finished, as well as one of the first on my rewatch list. Usually when I visit an anime for the second time, my opinion changes(even if only by a bit) but with this, I found it as enjoyable as before.

Rating system: Very Bad, Bad, Average, Good, Very Good

Story: Good
I personally liked this part a lot, it's well-written for the most part and provides a good time. Well, without going into spolier territory it's somewhat difficult to say a lot about this, but don't expect it to be the usual shonen(even it does have some specific elements) be ready to embark on a wild ride. I'll say it from the start however, don't expect fan-service(at least not the amount you find in the rest of anime), harem, romance or any other similar themes, it's purely focused on adventure, action, characters and their personal goals. Enough with the praise, I gotta say something bad about it too, nothing's perfect now, right? Actually, I'll include this when I talk about every arc in particular.
Spoiler section starts, skip to characters if you don't wanna see

Arcs(same rating system):
1) Hunter Exam: Average/Good
It set the pace for the whole story, it had it's great moments such as Killua and Gon "fighting" against Netero. It introduces the characters, the world and some necessary aspects of what hunters are. Alternatively, the pacing was a bit off and there weren't many astonishing moments. The reason I put this betwixt average and good, and not in one or the other is the discrepancy between my opinion(good) and how I think it should be rated objectively(average).
2) Zoldyck Family: Average
Nothing special but it did present Killua and his background more. That's all I got to say about it.
3)Heaven's Arena: Good
I'll start off by saying that I really liked this arc as I'm usually a big fan of this type of competition elements(if done right). It introduced nen, included Gon and Killua in their specific nen categories and had some awesome fights.
4)Yorknew: Very Good
Loved it, best arcs in my opinion. It introduced new characters and organizations, such as the Phantom Troop(which was really cool), and the Underworld Structure. The story was good, we also get to see the other 2 main characters again after the Zoldyck Arc. It had(again) nice fight scenes, a good plot progression and a good ending. We follow three storylines for the most part, Phantom Troop wanting to rob the auction, Kurapika's quest for revenge and Gon&Killua wanting to buy the Hunter Game. That said, there were 2 things I disliked: how overpowered Kurapika got and how weak the Shadows(I think they were called) were, they seemed like a big deal and ended up being destroyed easily.
5)Greed Island: Good
Firstly, this arc is objectively average, it's unrequired if I'm being honest. However, I really enjoyed it, we see Gon and Killua training and getting more nen knowledge, learn more about Ging and see a different type of fighting. That's all.
6) Chimera Ant: Good
I know a lot of people say this is the best arc of the series, I personally liked it less than the others. That said, it's still good, I just thought it was a bit too long as well as found the Ant King getting really strong, really fast as a downside. On the bright side, a variety of new and captivating characters are introduced, the action isn't missing anything and the plot is fairly interesting.
7) Chairman Election: Average
Pretty nice arc, Ging and Gon meet, we see more of what the Hunter Association is like, see some old characters make their comeback and get a decent ending(which isn't exactly an ending).

Characters: Good
(Minor spoilers)
They're fine, nothing too special, but diverse enough and with plenty of quirks to make it jump from average to good. They all stay, more or less, the same throughout the series. Gon's a meathead whose goal is finding his dad and becoming a good hunter, Killua's a former assassin and we get to see that a few times, his goal is making friends(I think), Leorio believes money's the most important thing and wants to be a doctor to save lives, Kurapika wanted to get revenge for his clan and recover their eyes(the Scarlet Eyes).

World Building: Very Good
For me, it's the best aspect. A bunch of different organizations(with different strength levels which makes it feel like the power isn't held only by one) and places are shown and there's also the Dark Continent(really hope it's gonna get adapted to anime). Otherwise, I'll stop here until I start going on and on about why I like this so much.

Music, Sound & Voice Acting: Very Good
It's good, not much to say besides that.

Animation: Very Good
Same as the previous category, can't say much besides that fact that it does justice to the fight scenes.

Final Thoughts:
You should really give this a try if you haven't before. There's a good chance you'll love it.

Final Rating: Between Good and Vey Good