Well, I know DOOM has to be revealed. I've signed up for the beta nearly a year ago when I got Wolfenstein: The New Order.
It would also make sense they announce the latest iteration of the proper Elder Scrolls series (ESO don't count, hoss.) since they've had an Elder Scrolls release on the previous two consoles generation (Morrowind on Gen. 6, Skyrim on Gen. 7). I honestly hope they wait a year or two however. ESO is being released to consoles on June 9, after the PC players finished beta playing it and got milked for subscription fees.
However, I'm really needing a new Fallout game. Not wanting - needing.
Or a new Dishonored game. The first one was fucking brilliant- a sequel which took the mechanics, tightened them up, and further expanded the mythos in the game would be insanely great.
It would also be interesting if they decided to make a sequel to Rage since the first one just kind of... stopped. No real conclusion or anything, just... ffft done.
Or, maybe they'll go flat out psychotic and announce games no one was really hoping for. Like a sequel to Brink. Or maybe a sequel to Wet (they can call it Wetter, and the app companion they can call Moist).