Dragonball-Z continues the expanding tale (no pun intended) of Goku and his friends.  Goku is now married to Chi-Chi and they have a son named Gohan.  When Goku's brother Raditz, a space pirate, kidnaps Gohan, Goku must team up with his arch-rival Piccolo to stop him.  From there, the story expands as everyone finds out Goku's true origins, and encounter enemies they never knew existed.

Review: There's just so much to say about DB-Z, I don't know where to start.  It was really the very first anime I ever watched on TV (backed when it was airing at 6:30 in the morning on either Fox or UPN).  I found it confusing because I didn't realize that the story spanned multiple episodes.  But after it started airing on Cartoon Network, I got the gist of what's going on.  It was incredible, the action sequences were so intense that I was literally on the edge of my seat.  It's definitely darker and more serious than Dragonball but I loved all the episodes right up to where they defeated Kid Buu.  After that, it sort-of went downhill.