I weighed up my options on this one, and then made my choice:
Father Damien Karras, introduced in The Exorcist
He's a great character, and seems to be the typical character in a film trying to do the right thing when there is lots of unpleasantness around him. He also has a complicated and tragic backstory with his mother.
For me, this all makes for a great, slightly flawed, hero character.
Day 16: Favorite Horror Movie Hero
Day 17: Favorite Horror Movie Heroine
Day 18: Favorite Horror Movie Love Pairing
Day 19: Favorite Horror Splatter Porn
Day 20: Favorite Horror Movie Location
Day 21: Favorite Animated Horror Movie
Day 22: Favorite Horror TV Series
Day 23: Favorite Horror that comes from a Book
Day 24: Best Horror Movie You Saw Last Year
Day 25: Favorite Classic Horror Movie
Day 26: Favorite Horror Movie Series
Day 27: Least Favorite Horror Movie
Day 28: Favorite Horror Movie Made for Kids
Day 29: Favorite Jump Scare
Day 30: Favorite Plot Twist
Day 31: Favorite Horror Movie