These might not all fit each of your criteria, but they're all post-series where either the Scoobies or Angel kept Spike coming back from her and they get together in the end.
Guilty Soul by Uncaged Muse
http://www.dark-solace.org/elysian/viewstory.php?sid=238Summary: Set in season 5 of Angel. A personal journal written by Buffy Summers just before the destruction of Sunnydale is found in the excavation Angel is heading. What will it reveal to the two men who love her and how will each react? NOW COMPLETE!
Heaven Sent by VampGirly
http://www.dark-solace.org/elysian/viewstory.php?sid=1670Summary: Buffy discovered that Spike came back and no one told her. It's too late for her to see him and tell him how she feels as he died again saving the world. Or has he? Disillusioned and heartbroken she attends one last gathering at Wolfram & Hart to say goodbye to those that betrayed her friendship and trust.
Hell Is In the Details by spike_heart
http://www.dark-solace.org/elysian/viewstory.php?sid=848Summary: Spike resurrects corporeally and Angel can't take it anymore. He betrays his childe in the worst ways possible: by selling him out of the family into slavery. --- DARK
If I'm Not in Love by Spikelissa
http://www.dark-solace.org/elysian/viewstory.php?sid=2317Summary: 146 days have gone by and Buffy still hasn't got over losing but walking away from Spike's demise. Devastated she has found a way to be with Spike. Unknown to Buffy and Dawn...Spike is alive well, un-dead. Will she follow through or will Spike come to the rescue?
Nothing Like Dreaming by lisa_dec
http://www.dark-solace.org/elysian/viewstory.php?sid=2073 Summary: Sometimes you get what you want, if you just want it enough. Buffy has a strange dream, or is it? Suddenly she is back in time, waking up beside Spike in a familiar ramshackle building.
Secrets and Lies by angelic_amy
http://www.dark-solace.org/elysian/viewstory.php?sid=5Summary: A world away from the Hellmouth, Buffy is moving on with her life. When a case brings her to LA she discovers something that had previously existed only in her dreams. Will she get the chance to voice her unheard thoughts before it's too late? Set in Season 5 of the Angel timeline, during the episode 'Damage'.
The pathway to hell (is paved with good intentions) by jamies_lady
http://www.dark-solace.org/elysian/viewstory.php?sid=2521 Summary: Long after Sunnydale Buffy is having problems in london and chooses a dreadful way out of her difficaulties.
We All Fade Away by Megan
http://www.dark-solace.org/elysian/viewstory.php?sid=551 Summary: Post NFA. Buffy stumbles upon the fight in LA by accident and the pain of it has her making realisations that have been a long time coming. What will she do now that she knows Spike came back and didn't tell her?