I didn't see a Green Lantern movie coming. But now it is. So maybe an Aquaman movie wasn't so far-fetched after all. After that... Krypto the super-dog? Sparkie the super-cat?
That being said, there are many good options still... Teen Titans. Wall to wall totty. Doom Patrol, Grant Morrison-inspired, wall to wall weirdness. Preacher... wall to wall psycho-violence.
And that's without even looking at the Marvel Universe. I've always been eagerly waiting for that Dazzler movie.