Dragon Ball Z had better action/fight sequences, but not much else unfortunately. The dragon balls became merely a fail-safe, and any meaningful skills and abilities the characters possessed became nullified by the question of 'who has the highest power level?' The highest power level wins - that's it. You wanna beat the bad guy, ya better power up.
Now having said all that, I grew up with dragon ball z, and have a special connection to it despite these flaws. But in all honesty, I think the original Dragon Ball was the best of the series.
And as for Super, its really just riding on the curtails of Z.