If my memory serves me correct (it might not) DB was more focused on adventures of kid Goku with interesting fights as side dish.
DBZ on the other hand was more "monster of the week"/"transformation of the arc" with some bullshit power levels that means nothing and fights as main focus (which were sorta boring for me (though I am sucker for new transformations), do yourself a favour and don't watch orginal DBZ but watch DBZ Kai).
DBZ was amazing during the Saiyan saga.... Went downhill after that incredible fast after each arc
Sure there are some amazing moments after that (SSJ3, Final Flash, Piccolo VS. #17, Etc.) but the show went downhill incredible fast... And that trend continued with GT.. Amazing moments, but just lackluster as a whole..
Super started out the same with the first 2 arcs(so bad, and so badly animated), but instead of going downhill it went uphill after that... (Tournament, Trunks, Survival)