My five year old son picks the episodes he wants to watch. At some point. we'll sit and watch them in some sort of order but at the moment he mainly plumps for the last hour of Attack Of The Clones and certain scenes from Return Of The Jedi. He's recently been allowed to watch Revenge Of The Sith and I think he enjoys that because of its previously forbidden nature.

I don't impose any kind of watch-these-films-they're-better-than-the-others mentality on him, mainly because I don't subscribe to that viewpoint.