Title: Bridges
Author's LJ/DWJ: tassosss 
Categories: Crossover
Warnings: None
Author's Webpage/Fic list: At AOOO
Link to story: Bridges 'Verse
Why this should be read:

Okay, I know that this is one of the all-time most well-known Stargate/Buffy crossovers, but I'm going to rec it anyway (if for no other reason than to update peoples' links, as the link I had for it is no longer good). It's not the most brilliant fic in the world, but it is solidly written and the best Xander's-Real-Father fic that I know of. The characters are in character, the always-difficult task of revealing secrets in the story is handled believably, and it's a very enjoyable story that I've come back to to re-read several times.