For my money, the 800lb gorilla of Sony's E3 press conference was the timed exclusive No Man's Sky, which will put each individual player on their own procedurally generated world, then allow you to fly off into space to discover other players' worlds, with planets generated infinitely. No Man's Sky looks like it could be really, really special. I don't think anyone could walk away from this trailer unimpressed.
https://www.youtube.com/watch?v=7hM8RdLNGPI