Which order to watch Star Wars?

[Abstract Actuary]

:::Warning, don't read this thread if you don't want to have the Star Wars story ruined for you.:::

If you were going to have someone watch the whole Star Wars series for the first time, in what order would you have them watch it?

By release date: IV, V, VI, I, II, III?

Or chronologically: I, II, III, IV, V, VI?

Assume that they know nothing at all about the story. What if they probably already know the backbone of the story (Luke, I am your father)? What would you want if you were watching it for the first time?

In my opinion watching either trilogy first ruins part of the mystery of the other trilogy. (RD: You know Anakin Skywalker's fate. Ch: You know that Luke and Leia are Darth Vader's children).