1] Ecolea's 'Changing the Guard' series, which is a Highlander/Stargate crossover.
2] dejla's 'A Kindness of Ravens', Highlander.
3] mhalachaiswords's 'Physics of the Spin, Atlantis/Gilmore Girls, and even though it's a WIP, I'm picking it [g]
4] strangevisitor7's 'Ghost Town', M7/SPN, a sentimental favourite since it was my very first exposure to M7, back when I thought Ron Perlman played Ezra LOL. And it's a great story to boot.
5] 'Wine of Wrath' by amonitrate, Highlander, though it's a tossup with her Iron Man story, 'The Priming Game'.