So my friend got into Dragon Ball. He finished the original DB series. So which one should my friend start with seterusnya Dragon Ball Z atau the Remake/Reboot Dragon Ball Z Kai?

I would say maybe the Remake Z Kai. I did watch both series original and remake as a child. I remember Z Kail being on Saturday Morning 4Kids Entertainment CW 4Kids network. Which one do anda think my friend Tony should start with next? Z atau Z Kai? atau does it not really matter which one to watch seterusnya in the Dragon Ball series? All I know is I watched both as a child DBZ than finished the series with DBZKai. Explain your reasons why. Thank you.