A Neural Interface, this would also double as dynamic water, super-real graphics, and fully breakable props as it would process through your brain. Just imagine it, you wave a hand and props spring up, a admin points at someone and they are banned. Also, this could be every mod in existence, you could go, “I want a exploding pie”, and there would be a exploding pie right there in front of you, then you could go “I wish to be a shapeshifter” and then you could transform into a melon, then you could go “I wish for bioshock to be ported to here”, and it would extract it from your memories (anti-piracy, you’d have to buy the game and play it, watching a video would not be enough, and best of all, it can’t be bypassed as it is a limitation). Also, you could get a little-kid-type minge, and make him melt, and he’d be scarred for life.
Well, maybe not the last one, as his parents would come on and go “WHAT HAVE YOU DONE TO LITTLE TIMMY” and burn out your mind, though there’d probably be safeguards for that, as well as a thing for replacing pain with tingling.
Sorry for the cluttered post, that would just be awesome. You could even have virtual food, and even though it wouldn’t fill you in real life, it would taste like it and you’d could feel it in your stomach until you disconnect.