Fortunately for this thread, bad horror movies outnumber good horror movies by 2-to-1.
An American Werewolf In Paris, Troll 2, Plan 9 From Outer Space, the two Halloween remakes, the Nightmare on Elm Street and Friday the 13th remakes, House Of 1000 Corpses, all Saw movies after 2, Gingerbread Man, Dracula 2000, all Tales From The Crypt movies (except the original). Dreamcatcher, Alone In The Dark, Ghost Ship, House on Haunted Hill remake, Anaconda, Maximum Overdrive, Exorcist 2, Hostel, The Happening, Nightmare on Elm Street (after 3), Manos: Hands of Fate, Friday the 13th (after 5 or 6, especially Jason X), The Leprechaun, Queen of the Damned, Feardotcom, The Haunting (remake), The Wicker Man...
And last but not least: Every single SyFy "horror" movie ever made.