For the skeptically prone Slayers fan, I've gathered a small collection of essays to support the X/F cause. Below are some articles that explain and justify the highlights of Filia and Xelloss' relationship. Read them; they might just change your opinion of the X/F couple!
-+¬ Essay #1
by Janet Clift
Quite a lengthy essay that discusses a few, notable X/F scenes, as well as why they are significant.
-+¬ Essay #2
by Esther Nairn
A very in-depth/comprehesible essay targeted at certain personality qualities that justify the X/F couple.
-+¬ Essay #3
by Chibi Ophelia
A formal essay that smoothly and creatively explains why Filia and Xelloss are a traditional couple, and not an alternate one.