There's really only one movie that "ought" to see in 3d, and that's Avatar.
Any other movie is "fine" but not really essential. Sometimes it's even straight up distracting.
It should be noted that a lot of fiction attempts to facilitate conversation, not to actually present an argument or viewpoint. There are some of the later, but they usually end up being garbage.
"Father: You gave me the gift of life without a gift receipt. As a result, I could not exchange it for something better. Allow me to repay you with this ugly sweater...without the gift receipt! Mwahaha!"
SA3 release date is anyone's guess. The only thing "for certain" is that it will be in 2017. And until the first draft is complete, even that is not guaranteed.