settiai was requesting recs for long, plotty AU fics. So I decided to make a fic rec post here - these are mostly stories I've recced before, but not collected together specifically as "long plotty AU fics", so some of you might appreciate it as a thematic post.
( Buffy )( Doctor Who )( Harry Potter )( Lois & Clark )( The Sentinel )( Star Wars )( Stargate )