"Me gustan esas tazas verdes."
Translation:I like those green cups.
The liking applies to the object and not the person/people, so if the object is plural so is like and the same if the object is singular, if you catch my drift. I THINK that like also takes the gender of the object. Excuse my Spanish but as an example if if was "we like that green cup" I think it would be "Nos gusta esa taza verde." or something fairly similar. I hope that helps, or at least someone backs up what I am trying to say.
Basically, from previous comments I have read elsewhere, I think you need to think of it as "to me, they give pleasure, those green cups."