Ok, so, the elephant in the room. At the end of the series, Goku, having spent the last few years (there is a jump forward after the defeat of Buu) training and raising his granddaughter Pan, Goku decides to abandon his family to train Uub, the reincarnated Kid Buu. Now, despite the English translation, Goku has never been the best guy in the world, caring more about pushing his own boundaries than the safety and wellbeing of friends and family; but leaving his family to train a random stranger for years is a dick move by any standards. It's interesting that Dragonball Super is being written as taking place between the defeat of Buu and the start of the tournament in the last few episodes of DBZ, Uub has been mentioned and Pan and Bra have been born in DBS, so just how "canon" the final episodes of DBZ remain is a topic of discussion among fans. I, for one, hope that DBS continues on past the end of DBZ and we have a more satisfying conclusion for the saga.
It will likely be a very long time before I brave another full rewatch of DBZ. Going over the Sagas I like best? Sure, will probably happen sooner or later, but with Dragonball Super, Dragonball GT and the DBZ movies to work through, I can get my fix many times over before then. Still, DBZ is a solid programme and well worth checking out if you've never given it a go; yes, 291 episodes is a big ask and not all of them are winners, but Dragonball has become such a huge cultural tent-pole that it's still worth your time. Much like Doctor Who or Star Trek, Dragonball has been running for so long some basic understanding of it is almost necessary to function in "nerd culture". If you've never seen Goku's first Super Saiyan transformation, Trunks fight Frieza, Gohan punch Cell so hard that Android 18 pops out or Majin Vegeta bitch-slap Goku, you're missing out on a lot of fun and should give it a try. Animelab has it all for free, so check it out!