1996, the year Dragon Ball Z was first brought to American soil. The series dub went sour and was canceled. In 1998, the Series was brought to the Toonami anime block on Cartoon Network. It was a hit, and Funimation decided to dub the rest themselves. Short and sweet, DBZ was the most original anime concept at the time, well that's what I think. Most original, other than it's predecessor, Dragon Ball. It featured Goku, a Saiyan from the planet Vegeta. Saiyans were an alien race with extraordinary powers. Goku faces great evil to protect the dragon balls from being used to wish upon evil deeds. The series, Dragon Ball Z: Kai, is exactly the same series as Dragon Ball Z. Except Kai contains a few minor changes. Dragon Ball Z: Kai contains better graphics and rendering because it has been digitally remastered, and is available in HD quality. The series also has a new cast, along with new introduction and closing fmv's. The songs for the fmv's aren't as good as the original. The blood has been taken away to make the series "kid friendly". That's about it, here is Dragon Ball Z: Kai in a nutshell.
You don't have to be on the computer, or have the DVDs to watch the series
The graphics and rendering is better, giving the series a new flair
The new cast doesn't interrupt the original "tone" of the series
The old introduction to the series fit better than this new one does (It just sounds chessy now)
They took away the blood from the series, making realism and deaths confusing and non-apparent it seems
DBZ: Kai is still DBZ, they need to make a new series to Dragon Ball, not recreate them
Basically, If you haven't watched Dragon Ball Z before, give Kai a try. I would also recommend Kai to fans of the series who wants to see the series burst to life again, especially with it's new look. But if you miss the blood too much, or don't like remakes, I wouldn't recommend this show for you.