Fili/Kili (NOT RELATED), Thorin/Bilbo. They met as two orphans in a group home in New York City and promise to be brothers forever. Kili hates himself for screwing that up by falling in love with Fili. (Or how Kili first brings together his family and then is afraid he screwed everything up.) Slow burn.
Cursed with obedience from a young age, Kili never let it break his spirit. Then again, he never had someone figure out the curse before his stepmother and stepbrother. With no one he can turn to, can he save himself, and more importantly Fili, from the curse? Fili/Kili Slash. (Kili and Fili are cousins in this, not brother, fyi)
Aulë and Yavanna, displeased with how their children fare during and after the War of the Ring, decide to do what they can to better prepare the world for the evil of Sauron. Unable to interfere themselves, they send two of their children back to the day Middle Earth was put on its current choice. Thorin/Bilbo Slash
Harry/Fred Slash. It's funny how one small action can create ripples that change everything. Harry's entire world is changed dramatically by one letter sent to him the summer before his 5th year. How different will the War be with the Weasley twins playing a more active role at Harry's side?