Ok. Dragonball. Easily the best in the entire world we know as DBZ. It chronicles the story of a child. Strong beyond belief. He goes on these crazy ass adventures with Bulma (hottest chick in DBZ), Yamcha who was definitely cool then, and Krillen who I did not like at first but grew on me. I love how he takes on real world baddies such as the Red Ribbon Army, realistically strong characters like Tien Shenhan and captures the heart of Chi Chi and he doesn't even know it. It truly captivates the spirit of Goku and makes you understand fully why he is who he is.
DBZ. Rivals a close second to DB. You almost really can't compare the two. It stops being about an adventure and more of a training to be the ultimate strongest. The world of DBZ is full of monsters stronger than they can possibly imagine and Goku fighting for his race that he barely knew anything about.
I like Dragon Ball Z more because the series is drawn better, you have way better characters and people finally turn into Super Saiyans, also you have way better fights in Dragon Ball Z. I never really seen the Dragon Ball episodes but I did read the books.