FFA Crossover fics

Am debating writing a couple of Buffy/NCIS crossovers for Twisting the Hellmouth's FFA (Fic For All) challenge. They want 2005 fics/drabbles by the end of the year, and there's a couple of pairings on the list that strike my fancy. Mostly:

Jonathan / Abby
Andrew / Abby
Buffy / Tony Dinozzo
Jonathan / Daniel Jackson
Jonathan / Cassie Frasier
Xander / Veronica Mars

Hm...