Fic Title: At the end of her rope
Link: here, at FF.net
WIP?: Yes, but the author updates every night, sometimes with more than one chapter
Why This Must Be Read: Because it's visceral. The story starts at season six, when House finds out that Cuddy is dating Lucas, and goes from there. It deals with love, friendship, and shows a House getting more mature after Mayfield, and a Cuddy who's slowly losing control of her own life. It's an interesting change, since it's usually House who screws up and Cuddy who saves him.
Some times, the angst is so bad that it hurts you, but it's beautifully written. All the characters' acts and decisions, even the most extreme (and let me tell you, there are some very extreme things here), are in character. It's one of the best pieces of fiction I've ever read. And don't you worry - there is a happy ending, the story just hasn't reached one yet.