Good luck OP. I've watched the first DB series twice-over fully (in Japanese), both times with the intention of going through DBZ right after. The farthest I've gotten in DBZ is the end of the Garlic Jr. saga. The Saiyan Saga is pretty damn good, and even some of the Namek stuff is good. The battles are prolonged but bearable if you're marathoning episodes (since you don't have to wait as long to see the outcome). Then the series goes, pardon the phrase, full retard.
Think about this: the fight between Goku and Frieza should be epic and intense right? I mean Goku goes fucking Super Saiya-jin for the first time, and Frieza is an awesome villain, so it should be great, right? WRONG. It is a 19 episode,
literally 4 hour long borefest of repeated animation and false climaxes.
So then this awful battle finally finishes and you're ready to move on to the next major plotpoint.
NOT SO FAST THERE. First you have to go through a
9 episode filler saga that no one could possibly give a fuck about, because it's obvious that none of this has any impact on the main plot.
That was it for me. I
love the first DB series. It's charming (especially in the original language, since humor and cuteness are so dependent on good delivery), unique, genre redefining, and has genuine character and tonal development. I cannot stand DBZ. It is an obscene waste of time.
And the thing is, Kai is so much better, but even it got screwed up in the end because of the music debacle and subsequent switcharoo. So now there's no definitive DBZ anime. I'll just have to read the manga sometime.