It's good for fights and explosions. It's severely lacking in the plot department, and if I remember correctly (been years since I've watched that), a lot of the characters (if not all) stay the same since first being introduced.
I think 60% of the reason why I say it's a great anime is because so many childhood memories are tied to it. Humans can get defensive of anything, even if that anything is complete garbage, if it has sentimental value (though I guess it wouldn't be garbage to them).
I'm not saying DBZ is garbage, in fact it's a good action anime to watch as long as you're not looking for good plots and character development.