I know, I know it's been a while. Sorry! On a happy note, tkh1011 is going to be doing some recs as well, hopefully in fandoms I'm less familiar with. On to the rec
Bridges by Tassos
After the collapse of Sunnydale, Jack gets a call about a woman he knew over twenty years ago...and the son he didn't know he had.
An honest to God classic of the Buffy xover genre. This is just plain a "must read" if you haven't yet. It's the cliche, right, you've seen a gazillion horrible "Xander's Real Father" fics and now I give them a chance based on the possibility they might be as good as this one. Knowledge of both series is necessary.
http://www.tthfanfic.com/story.php?no=3138