Dragonball Z even though not the first season but many considered it the best season in the whole Dragonball series. It first debuted in 1988 as Dragonball as the first season. Dragonball was created by Akira Toriyama in which turned out to be very sucessful series. 1984 was the year the manga was created. Dragonball Z is the sequence to dragon ball and shows a growned up goku who is from a alien race known as saiyans. Known as the protector of earth, him and his friends fight off threats like other saiyans or alien beings that are in search of the dragonballs and the destruction of earth. When all seven dragonballs are placed together and the right words are said a dragon known as shenron comes out and grants any wish you want.
D.Gray Man is a manga based series by Katuro Hoshino. It tells the story of 15 year old Allen Walker and his allegence to a orginaztion of Excorcist that used an subtance called Innocence to fight the Millenium Earl. Millenium Earl uses his army of akumas which are souls of dead people wish backed to life and then turned into demon soldiers. It aired first in 2006 till 2008, the series was put on hold because the manga stopped due to an injured wrist of Katuro Hoshino. Though it has potiential for another season because the anime is nowhere near where the manga stopped, it wont continue till Katuro Hoshino heals.
Yu Yu Hakusho first aired in 1992 throughout 1994 with a list of 112 episodes. The manga series was created by Yoshihiro Togashi in which later had it's own anime series in Fuji television and also reached out to cartoon network with english dub. It's about a 15 year old boy named Yusuke Urameshi who gets killed by a car crash and comes back to life as an "Underworld Detective". He has solve cases that involve demons doing crime. Later on it focuses on him improving his skills and going into tournaments to become the best fighter.
Naruto was created by Masashi Kishimoto. It's manga series started back in 1999 and still ongoing today. The anime series aired in 2002 and still ongoing depending on if you're refering to shippuden. It is about young parentless boy named naruto, who has a past that he does not know of.. Belonging to the hidden leaf village in which he was hated for being a trouble maker, he sought to become the hokage(leader) so that everybody will acknowledge him. Futher in the series, he's hunted for the 1 out of 9 bijuus that was placed in him by the akatsuki and later turning to the most important character and only him could save the world and bring peace.