I'd recommended some of the following fics on the old rec. thread, but I decided to re-post (and update) when I realized a lot of newer Kittens were probably unaware that many of these gems even existed. I've got more to recommend, but I'll start with these. I've grouped them by length.
Longer fics:
Tempus Fugit by LipKandy
This may be the most lyrically written W/T fic I've ever read; its only equal imo is Neverland. Tempus Fugit takes place in the Fall after S6, which has unfolded as per canon, and also in S4. (It's a time travel thing.) It's a story about second chances, for Willow, for Tara, for Buffy, and for Faith. It's got a love scene that remains, for me, the sine qua non of emotional intimacy and a plot development that's gripping, unexpected, and emotionally satisfying. There are two other stories in the series.
Tempus Fugit-S4 is a prequel of sorts, which takes place early in Willow and Tara's friendship. It's lovely as well. Tempus Fugit-Absolute Zero takes place as a consequence of the events written in S7, but takes place in an alternate season 4 timeframe (it's a time travel thing.) Unfortunately, Absolute Zero is a work in progress, and it's been quite some time since LipKandy updated. Oh well. Two out of three ain't bad. In fact, they're exquisite.
On Second Thought by Antigone Unbound.
I put off reading this story for the longest time because the teaser said that it was an alternate version of New Moon Rising, in which Willow chose Oz over Tara, and I didn't think my heart could take it. Ah Mary, I never should've doubted you; On Second Thought is a fabulous story that really delves into the complicated relationships between Willow, Tara, and Oz. Those of you who are reading
As Time Goes By or who have read
Gods Served and Abandoned know that Mary is a master of character and dialogue. You will love this Willow and Tara -- and this Buffy. And you will crack up laughing at the funniest "coming out to the Scoobies" scene I have ever read. My only quibble with this wonderful fic is with Oz. I've always been a huge Oz fan, actually, and I have a hard time reconciling Mary's take on him with the Oz that I know (if that makes any sense). That hasn't stopped me from re-reading this story at least a half dozen times....
What's Your Tale, Nightingale by KiwiAlcyone.
I read this fic over two days while stuck home with a nasty cold and it was the *perfect* medicine. It's an AU fic set in 1957, a romance between two women from opposite sides of the tracks. In KiwiAlcyone's own words, it's a "love story between our two girls set much in the style of the romance films of that period. I don't want to give too much more away than that. Other than the settings are New York and Paris, the music is rock and roll, the slang is a little weird... oh, and the world is not about to end in any hell dimensiony type way." This story is often screamingly funny, occasionally gut-wrenching, and very, very sexy. The ending is a little unrealistic, I think, given the time period in which the story is set, but that's the only bone I have to pick with KiwiAlcyone's remarkably rich and compelling story.
The River in Me by Triscuit7
The River in Me is a "missing scenes" retelling of S4 starting just after "Who Are You," and focusing on the growing W/T relationship. It is intensely sensual and deserves every bit of its NC-17 rating. While I'm a fan of River I actually don't like it as much as her
The Edge of Silence, which takes up where River leaves off. Silence is a much bolder reimagining of S4--developing an original plotline to go along with canon. Sadly, Silence is unfinished.
Shorter fics:
Vignette Series by Sassette.
Sassette has recently started adding to this magnificent series of captured moments. She's up to 45 now, and we're the richer for it every time she adds another. The vignettes range across time from childhood to future, but I confess that my favorites tend to come from S4, especially vignettes #2, 31, 34, 42, and 45. But I love them all.
The Laundry Diaries by Trom DeGrey
Trom DeGrey has written a terrific duo of AU vignettes, covering the same ground from Willow then Tara's POV. They're sweet, they're funny, they're meditations on the meaning of bravery, the ways that ordinary events can produce extraordinary moments, and life from the perspective of the third shift. And they've got Diane--a multiply-pierced grandma who just jumps off the page and wraps you in her arms! Don't let this one go by.
Collected Short Fic by Jixer This is a remarkably diverse collection of stories, some canon and some AU, some quite dark and others pure fluff. Jixer has the ability to paint a rich world in a sentence or two and to pluck emotional responses from the reader like a guitarist. My personal faves include 'Saving Ten Dollars and Postage" and "Bedtime Story."