Despite criticisms regarding translation accuracy and "Americanised" characterisations (like turning Goku into a more traditional superhero), this dub is credited with making DBZ a global phenomenon. Where to Legally Watch and Download DBZ
You can stream Dragon Ball Z with the Funimation dub on various official platforms, including:
There are some sites which allow free watching of contents.
Funimation originally partnered with Saban Entertainment and Ocean Studios in Canada to dub the first 53 episodes (condensed from the original 67). This version featured heavy censorship—characters were "sent to another dimension" instead of dying—and was often looped on Toonami due to a lack of new content.
Do you have any specific questions about these options or would you like more information on how to access Dragon Ball Z with the Funimation dub?