Stargate/Buffy Starting Over
Premise: Joyce, Willow's parents and Xander's parents die in the same "accident" and Buffy finds out that her father isn't who she thinks he is.
1) Changing the time lines around: Buffy came to Sunnydale during her freshmen year of high school. Also Buffy became a slayer on her 15th birthday.
2) Jack O'Neill coming to Sunnydale to collect the daughter he never knew about but ends up going back to Colorado with four kids instead of one.
3) The gang is still in high school.
4) The last several years of Stargate has never happened, set the story earlier in the series.
5) Buffy refusing to leave behind Dawn when social services can't find Hank.
6) Buffy using her pout & tears to convince Jack to become Willow & Xander's guardian when no other relative can be located to take them.
7) Willow bonding with Sam, Sam finally found someone who actually listens to her when she starts to talk tech and can understand her.
8) Jack & Xander bonding over The Simpson's and twinkies.
9) Dawn developing a crush on Daniel, she can sense that he use to possess a different form (i.e. when he accended).
10) Think up a creative way for Jack to find out about Buffy, Xander & Willow's nighttime activities. For example, Jack is doing laundry and finds the kids cloths caked with a gooey substance and takes it to SGC to have it tested, etc.....
11) Jack having to buy a new house because the current one is to small. Show the humor of house hunting when Jack brings the four kids with him.
12) Jack taking the kids on a fishing trip, again show the humor in it. For example the different styles of fishing the kids employ, for example Buffy catching a fish with her bare hands, Xander using twinkies as bait instead of worms, etc....
13) Jack giving his new "kids" a tour of the less restricted areas of the Mountain, of course they escape from their guide and go exploring on their own.
Secondary storyline: Giles staying in Sunnydale as Faith's Watcher, she lives with him and does not go evil.
She still has issues but Giles is helping her with them.
Mini-Jack is to somehow "think TPTB" end up going to Sunnydale High School and becomes the first member of Faith's new gang/group. Buffy's group is the "Scoobys", think up a name for Faith's group.
Mini-Jack finding his calling in Sunnydale, a place where he can use his knowledge to help save people and keeping the world safe.
If you want to bring Angel into the storyline, three options:
1) Angel died before his relationship with Buffy got to the sex level. After his death he became a whitelighter (borrowing from Charmed) and after Willow moves to Colorado Angel is assign to be her Whitelighter.
2) Angel(us) never was vampire, instead he works at SGC and thats how he's meets Buffy and they start flirting with each other much to Jacks dismay.
3) Angel(us) is a Tok'ra and he meets Buffy at SGC and she starts flirting with him which Jack really hates.
> Buffy: The Vampire Slayer