I'm looking for some happier Season 6 rewrites. Ones with either Buffy not dying at the end of Season 5 or the resurrection happens, but they grow into a healthier relationship from the quiet understanding they initially had at the beginning of Season 6. Some good examples would be His Girl by dreamweaver, Unwrapped by Holly, and Love's Gift by pfeifferpack for the first type and The Ghost in You and Fallen Angels both by BuffyMeetsSpike for the latter.

Doesn't have to be stories without angst as long as the Spuffy relationship is better than the toxic abuse we got in the show and any length is fine. I've read so much fanfic, but I'm hoping you guys will be able to recommend some that I might have missed.

Absolute must read you have probably already come across for a tender change to S6 - Et Lux In Tenebris Lucet by Enigmaticblue
Spike manages to save Dawn, but pays a terribly high price. Will he be able to find meaning in his suffering?
dark-solace . org/elysian/viewstory.php?sid=1046

Another you probably already know is Niamh's Origin series.
dark-solace . org/elysian/viewseries.php?seriesid=66

Payback by dreamweaver is not 'happier' but is about positively changing S6.
On his way back to Dru after 'Lover's Walk', Spike suddenly finds himself transported to his crypt the night after 'Smashed'. Horrified that he, a master vamp, should have been tamed and furious at how he's been treated, he blames Buffy for everything and is determined to pay her back in spades.
spikeluver . com/SpuffyRealm/viewstory.php?sid=35872&warning=NC-17

A Grain of Sand by always_jbj
Set in Season 6 somewhere around 'Life Serial' and goes very AR from there as slayer and vampire find themselves scouring dimensions. Will their search be in vain? And what will they learn along the way?
bloodshedverse . com/stories.php?go=chapters&no=392

Past Glory by Sandy
S5 up to Tough Love, AU after that although elements of S6 will appear throughout the story. Spike manages to save Dawn from Glory for good. Will Buffy and the Scoobies begin to accept and appreciate him now?
nocturnal-light . net/fanfiction/story/194/Past_Glory

And Then She Knew by Addie Logan
Spike does something different – faster and more clever – and everything changes. (Goes AU during "The Gift")
nocturnal-light . net/fanfiction/story/338/And_Then_She_Knew

'Pillow Talk' by Miss Murchison is a terrific S6 rewrite.

This fic begins as Buffy tries to cope in early Season 6, and begins to deviate from canon after a few chapters. A slight change in circumstances, a different decision or two, and you wind up with very different results.

http://home.mchsi.com/~missmurchison/Pillow_Talk.htm

Note that this is a WIP, but it ends at such a good place that it's very satisfying nevertheless.