Sad Dark Crossover
Pinkie Pie is being tormented by horrific nightmares. Unable to deal with it by herself anymore she seeks out Twilight's help, but will it have been the best decision when she finds herself alone in an abandoned, fog filled Ponyville?
A little late, I know. Anyways, I chose this fanfic for the day because it's a really good dark/sad fanfic. It's not like Cupcakes dark. It's...kinda what you could call psychologically dark. What's also great about this fanfic is you don't need to have ever played Silent Hill or even know anything about it to enjoy this fanfic. Hell if if weren't for the crossover tag, you might not even know it's a crossover. This story was very well written and as you read, it leaves you wondering what's going to happen next. I give this a 9/10 for being a unique fanfic.
Also, there's more of them too.
Silent Ponyville 2: http://www.fimfiction.net/story/4868/silent-ponyville-2
Silent Ponyville 3: http://www.fimfiction.net/story/16687/silent-ponyville-3 (not sure how good this one is since I'm not sure I ever got around to finishing the first chapter)