All right. So I've got a craving for some specific kinds of crossovers. I'm hoping you guys can help me find some:

SPN/Buffy crossovers that take place pre-series (or early series in the case of Buffy), in high school. Like, Sam and Dean moved around a lot as kids, right? So what if they just happened to move to the same school as Buffy? Maybe at the same time she moves to Sunnydale, or at her old school. I'd like gen fics for this, focusing on the characters' reactions to each other and not so much on the overall mythology of either series. I'll accept in-fandom pairings, but please no cross-fandom pairings (i.e. no Dean/Spike or Dean/Buffy fics).

I'm also looking for SPN/Dark angel crossovers where Sam and Dean meet Alec (or another transgenic) sometime after the start of Supernatural. I'd like the characters from both series to meet as adults, or at least older teens. Time travel fics would be awesome, especially if it's a transgenic thrown into the past. Again, I'd prefer gen fics for this but I'll accept any pairing that's not cross-fandom. Something like this fic, for example.

Self-recs are awesome, as are regular recs. Thanks!