Ooookkkkaaaaay, first up, go read 'Knight Falls,' by TJ. Can be found at PM or RalSts Website . You really have to read it...I don't wanna give too much away...uber, knight, lady, T/7, slash, good good.
Then, when you've finished that, scroll down the page to Ohyjo's fic, and read 'Profit.' Voyager's back on earth and everybody seems settled, but then tragedy strikes, throwing everybody's favourite engineer and borg back into close quarters. Very cleverly done, you must read. Go on. Go on, go on.
Try three of the fics by Sasha Chase (FOunder of Slayer Pride) in which Faith goes to L.A and meets Kate, but Buffy is on her trail...'A Whole New Scene,' 'Restitution,' and 'Em-whata?'. I go back to this series every once in a while, and enjoy it every time. Found at Slayer Pride .
Another series I go back to again and again is Pat Kelly's 'Who am I?' Series. Goooood. Also found in the archive at Slayer Pride.
If you would like to read a brilliant, bittersweet Faith/Kate tale, try 'The Way, Way Back,' by Liz Estrada. It can be found in the archives at Forgotten Hearts. Also at Forgotten Hearts are a number of stories by an author called Eos Dew, and they are all good, my favourite being 'Dancing at Aphrodites Lounge,' where Faith helps Kate catch a killer by going undercover at a local bar with her.
If you have a lot of time and patience, and don't mind not a lot of slash in a slash story, then Pink Rabbits Series 'Bits and Pieces,' is for you. Starts from the beginning of the first series of Stargate, where Sam and Janet meet for the first time, and details their growing friendship and the budding feelings they begin to have for each other. Slow to build, but with storylines that mesh pretty much seemlessly into the series canon and a slow building sense of anticipation and feelings between the women that leaves you going 'Just tell each other! Please! I can't take much more!' Really very, very good, and a must for those people (Like me, I will admit it) that love those moments in films where the relationship is just beginning and you can almost see the feelings in the air. You know what I mean. Or maybe you don't.
In Bad Girls fic, check out Two series' by RalSt, 'Talent For Hire,' which centers around the Larkhall Talent Agency and it's fiery Scottish manager, who meets a tall, dark, beautiful Tax Inspector by the name of Nikki Wade, and 'Not Quite An Angel,' In which when Nikki Wade dies, she's assigned to help a woman called Helen find her true path in life. Both are AU (is it AU or Uber? I forget.) And are as yet unfinished, but it's well worth spending the time to read what's there. FInd them at RalSt's own site .
And in Xena fic lies one of my most read two-parters ever: 'It all began with a Trout...' '...and continued with a skunk,' a hysterically funny series by Alexiares found at The Pink Rabbit Xena Archive. I re-read this about every three months or so. Back to Pink Rabbit again, but this time to their Alien: Resurrection fic. The Pink Rabbit's themselves have written a kick ass series called Alien: Odyssey which I've read at least four times. It starts just after the end of the film, and goes from there. I really enjoy it every time.If you're looking for a lot of funny, touching, good, angsty, sweet or sexy Torres/Seven, try Perfect Misfits .
One site I drop in on regularly is Pink Rabbit which has a huge number of fics, all f/f, and in almost any fandom you would want. (focuses mainly on sci-fi/fantasy shows, but a sizeable amount of ER, L&O, CSI and anothers also to be found).