Well I'd say:
Fireworks by Goldilocks
Summary: As teenagers, Buffy and Spike fall madly in love. They never imagined, on the night that they made love for the first time beneath the fireworks of Sunnydale Day, that Buffy would become pregnant. After giving birth to their daughter, Dawn, she decides that she isn't ready to be a mother and leaves both Spike and her child. How will Spike react five years later when she suddenly breezes into town to see them?
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=7355&warning=NC-17Father Knows Best by TammyAsh666
Summary: Dawn Pratt is tired of all her friends having a thing for her father, so she stops inviting them over to her house. She takes a chance on Buffy Summers, a new friend of hers, not realizing that was the one girl she never should have invited over.
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=34251Learning To Breath by TammyAsh666
Summary: William is married to a woman named Elizabeth and expecting his first child, but there were complications and he ends up having to raise the baby on his own. He puts out an ad for a nanny and when Buffy shows up to apply for the job, he gets the shock of his life. Nominated at the Love's Last Glimpse Awards, Lost in Spike Awards, and Cradle of Humanity Awards.
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=21760Light in the Dark by msperfect [PG-13]
A rich obnoxious single father needs a nanny for her 6 month year old daughter. Guess who comes to help? Can she turn him back to the man he was before?