Shit... I haven't seen almost any of these movies.
Scarecrows was abominable. Literally toxic. Except for the extremely interesting ending, I don't think there's a thing that movie got right. Wasting the potential they might have had to make The Ultimate Scarecrow Movie.
So, I'm going with Children of the Corn III. Because they got that fuckin' scarecrow RIGHT! That thing was awesome. And terrifying. Too bad it didn't play a bigger part in the film.