This was my favourite anime when growing up, on par with Dragonball. It is one of those animes that you know helped spawnother action, fighting, fantasy and 'powers' in Anime.
Nen, was a great instrument to the series and the different variations of it, we can already see this as 'Reiatsu in Bleach', 'Chakra in Naruto' etc. Remember that Hunter X Hunter was before these! The manga was