I really need to rewatch Split. It left a great impression with me, but I don't know if that's just because of the ending or not. That was a holy shit moment and I'm so glad it wasn't spoiled for me. Gotta rewatch it though and see if the rest of the film holds up.
For me it holds up for totally different reasons. I looked at it as a orgin story the second time around and it was obvious on the second pass.