So before I write this down I should clarify what I consider the definitions to be for each of these categories. Hopes: Things I want to happen that are semi-likely to happen. Dreams: Things I want to happen that are SUPER unlikely. Predictions: Realistic expectations.
Sony:
Hopes: More Death Stranding and Shenmue III, Rez II (I've said it before and I'll say it again, this is more likely than you think), Bloodborne II.
Dreams: All of my hopes + DMC5 and a big budget new IP.
Predictions: A more restrained show compared to the last two years, but their lineup is in a good enough state that even showing stuff already announced would still make for a killer show.
Microsoft:
Hopes: A slate of games that are unique or at least have a good hook. Not a heavy reliance on existing franchises. Something new.
Dreams: Honestly, after Microsoft shanked Scalebound, I have been super pessimistic on them. I guess OG Xbox Backwards Compatibility with Jet Set Radio Future would help. Maybe an apology?
Predictions: A slate of very good looking games. Crackdown 3 will be a highlight that will sell Scorpios.
Nintendo:
Hopes: Mother 3, Metroid, Pokemon, and a great showing for Mario Odyssey.
Dreams: Again, kinda like my hopes, but Animal Crossing out this fall, Persona 5 + on the Switch, and a better VC system would rock my socks off. Beyond Good + Evil 2?
Predictions: A fun but conservative showing like E3 2013. Unlike that show, which was not enough to turn around the struggling Wii U, this show will do just fine.
Might edit this post later to add third parties.