Just to clairfy something-I've seen DBZ, I admit, in English.
The first season, where they fight Freeza is good. Then, due to it's popularity, they made about a thousand other episodes. (that were crap) Past the part with the Androids, it just got annoying.
The story is based around the characters of Goku, Gohan, Krillin, Piccolo, Bulma, Vegeta, Trunks, ChiChi, Gotenks, Goten, Videl, exc...there are a lot. They generally beat up the baddies and are the good guys. It's a fighting show.
The over use of fighting with no main theme made DBZ annoying after the first two or so seasons.