Jumping in with some recs! This doubles as a contribution to Femslash February: two lists of 50 f/f fics, one posted after the last halfamoon and the other posted just now.

ALIEN SPACE LESBIANS of the FUTURE: Recs from series featuring some combination of aliens, spaceships, and futuristic technology. And lesbians, obviously.
Fandoms: Doctor Who, Sarah Jane Adventures, Battlestar Galactica, Caprica, Red Dwarf, Star Trek, Better Off Ted, Lilo & Stitch, Animorphs, Kim Possible, Xenogenesis Series.

Lots of yuri! (Mostly canon!): Anime/manga recs, ranging from "a developing f/f romance is the main focus" to "plotty ensemble stories where the canon f/f couple plays a significant part" to angsty pining to various flavors of darkfic.
Fandoms: Hellsing, Sailor Moon, Madoka Magica, Revolutionary Girl Utena, Read or Die, Maria-sama ga Miteru, Serial Experiments Lain.

Needs tags for: Red Dwarf, Better Off Ted, Animorphs, Kim Possible, Xenogenesis Series, Puella Magi Madoka Magica, Maria-sama ga Miteru