Been watching Hunter X Hunter (1999) and really liking it so far, Killua and Gon have me smiling from time to time, Leorio makes me want to hit him upside the head but I still laugh sometimes at him and Kurapika is pretty cool too.
I loved the '99 series, it was one of my first anime fandoms (the first I watched after Pokemon and Detective Conan in Arabic when I knew what anime was!).
There's rarely filler, but when there is, it's some of the best stuff the series has to offer because it's so rich and necessary and beautiful (the episodes on Whale Island where Killua learns to value life and receives genuine maternal affection is so beautiful...).
The colour scheme is so moody and the way angles and perspective are used is so theatric, Nippon animation was also the studio responsible for World Masterpiece Theatwr anime and it shows—they make up for limited budgets (and off model art here and there) with sheer style and Ghibli-like attention to detail and human emotions and body language. I recommend their other anime like Romeo's Blue Skies (warning: endearing and with a beautifully deep friendship like Gon and Killua's, but VERY heavy, it's about children working as chimney sweeps...)
(For a pokeani treat, hunt down the pilot episode of Hunter x Hunter to hear Gon voiced by Matsumoto Rica [Ash/Satoshi's seiyuu!], it's so cute and feels just like him, trying to save the fox-bear cub from being killed...)
It only goes up to Greed Island, so you gotta switch to HXH 2011 for Chimera Ant Arc and New Chairman Election Arc, but the crisp and clean modern art and animation is also beautiful, if less artsy and the angles more mundane (not as much unique direction, BUT very consistent, very detailed, and polished, Madhouse is fantastic in quality with some stylish scenes too!).
The score is okay or just bad in some parts though (there is this weird jaunty piece they use while awful things are happening, like people being hunted in Chimera Ant Arc which is dissonant in a funny way but I don't think it's intended, it's such a bleak arc...).