Beetlejuice would be fantastic, anything Tim Burton really. Sleepy Hollow is my number one I'd love to see (although while successful at the time, I'm not sure if there's an audience for that film these days), but Beetlejuice would probably be next in line. If they can pull an original maze out of him, that'd be insane and lines would be massive. Same with Guillermo Del Toro, I remember thinking that'd for sure happen after Crimson Peak, but nothing ever came of it.
Opening up to WB would set us up for an amazing lineup next year. Conjuring, Annabelle, The Nun could each get their own house, as redundant as that may seem, but they're each successful as their own entities. IT is the next obvious one, plus getting Jason and Freddy back. I really hope they try to strike the TCM remake again one of these days, as I truly believe it was the overall tone of that property that made Back in Business the best maze in history. It's been quite awhile and I'd love to see what they can do with it now. The aesthetic of the original only works so many times. As great as Arkham Asylum would be, I don't see Uni doing it -- just seems a bit off-brand and like copying WB's event.