Goku's had a lot of different forms from the original series, to DBZ, Dragon Ball GT, Dragon Ball Super, and most recently Dragon Ball DAIMA.

Dragon Ball Daima revealed that Vegeta had indeed also unlock the Super Saiyan 3 form rather than seemingly skipping over it as teased by the future events seen in Dragon Ball Super, and this form ...

Dragon Ball Super's power scaling means that the series' forms are leagues stronger than anything seen in Dragon Ball Z, & are only getting stronger.

Vegeta doesn't have as many transformations as Goku, but that's simply because the Prince of All Saiyans doesn't need them.