Here are mine:
The burial scene...I just feel like that whole scene could've been a lot more brutal and evil Mia could've been a lot darker when she was taunting him (like Reagan in The Exorcist taunting the priest)...also the red dress was never explained.
In the tree rape scene (which I happened to like), when the the branches come out of the demon girls mouth, that is probably the one and only CGI moment that I thought looked very digital and fake.
When David pulled the dead dog out from the crawl space, it totally looked like a stuffed animal.
Most of the beginning dialogue...the actors struggled through most of those scenes in my opinion...they performed much better later on once there was a bit more drama.