Of all the games at E3, the one I am most anticipated for and wishing it could be there is an indie game in development called Titanic Honor and Glory, a detailed and fully explorable recreation of the RMS Titanic's maiden voyage and sinking which is sure to win a lot of awards for its accuracy and attention to detail. IT's also in Unreal Engine 4, used for the recent Kingdom Hearts games.
For more information, feel free to visit their site and be sure to donate to them as well as trying out their environmental demo: http://www.titanichg.com/