These are canon ones. I know a lot of people don't like Spike with someone else but I have a fondness for them (I'd have him!!

)
Favourite is
Prophecy and Warmth by The Bear
She tries not too think of him, she is afraid if she does he will consume her and there will be nothing left of her for the daytime. **Look's like my weird one shot is becoming a story**
That doesn't tell you much but....read on!
Sort of within the criteria, Eowyn315 wrote an
Alternative Season Six that has a Jacob and a Susan (!) making up a love-ish and wobbly "square" (at least in the later instalments). It's more in the 'Buffy wants a normal relationship' genre, but still... Also, I don't think this tale gets near enough love.
Slaymesoftly's
Lovers and Lethe also fits - if you'll accept amnesia and a spell
Buffy comes to LA looking for amnesiac Spike. Set one year post NFA - things aren't quite what they seem, but it takes them a while to figure that out.
Divinity by Sass Angel. Warning being the same as above
Take one Slayer with some serious guilt issues, stir in one unsouled vampire with some significant memory lapses and what do you get? A post-grave fic like you haven't seen before. Four part conclusion. Yeah, I was suprised too.
.......and a complete stretch of the friendship is
None Other Than You: A Spuffy Story by nonothrthnme. There's the almost fiance Tom who's worth the price of admission.
Buffy's got a life now. She's taken up normal, nice and cosy,No weird, no wild, no fires burning, just a staking here and there. No big. Not like she craves it, or something. Or someone. Then it all hits the fan with a dark threat to the line of Slayer, her line. With hell comes fire, a flash of heat that beats in her pulse, makes her feel alive, vital, useful, and an old flame is just the one to bring it: he and no other.Hope there's some you haven't read that fit