This is probably one of the best anime I've ever watched. This anime is a masterpiece, so chances are you've heard of it a lot of times. And it deserves the recognition it has received. The story, the plot, the fights, character development (of all characters), everything- is simply amazing. I personally haven't watched much anime (hunter x hunter was my 7th anime) but I guarantee, you can trust me. [Little spoilers ahead]
So basically, the best thing about this anime is its fights. The fights are simply amazing and as the series progresses, they get better and more intriguing. Especially the fights in which Hisoka is involved (main antagonist of the first arc and also exists throughout the series, but unfortunately does not get much screentime except in the first and second arcs). It's not like everyone is strong from the beginning- they train like hell and get stronger but not to the point where they get overpowered. Character development, sketch and redemption have been shown appropriately by the manga artist as well as the animators. Fillers are also not there, just a bit of elongated scenes that too only in 3-4 episodes out of 148 episodes.
Screentime is, I must say, a pretty complicated thing in this anime. Some characters who deserved screentime did not get enough screentime, but justice was served to others who deserved it (though I must say, characters that don't deserve screentime didn't get it either). For example, Killua (who is a close friend of Gon's, the main protagonist) gets a lot of screentime, and he absolutely deserves it. But on the other hand, characters like Leorio and Kurapika (who are also Gon's friends) didn't get enough screentime. I haven't read the manga and both the anime are NOT YET complete, so that might be the reason. Same for Hisoka and Illumi. It's evident that more is to come from their sides.
The fights are amazing, and they progress smoothly throughout the series. Nen abilities are nicely portrayed (though you might get confused about Nen in the beginning if you don't listen carefully, although you're very likely to become well-versed with Nen later even if you're confused in the beginning) and the fights are quite amazing. The characters aren't overpowered, and characters with potential get to fight a lot.
There are 6 arcs, spread across 148 episodes- The Hunter Exam arc, the Heaven's arena arc, the Phantom Troupe Arc, the Greed Island Arc, the Chimera Ant arc and the Election arc. You won't get bored for even a minute. My personal favourite are the Hunter Exam and Phantom Troupe Arcs.
So, I'll end it here. I'll say this again, the series is NOT COMPLETE, the manga hasn't been completed and obviously, the anime hasn't been either. So don't feel disappointed if you want more, if 148 doesn't seem enough. This is one of the best anime of all time, one of those masterpiece (it also inspired Naruto, which is even more famous so just imagine how good this one is). Absolutely recommended for all ages (not recommended for below 12 lol). Have a nice day, keep watching anime :)