Lots of their RPG books are on sale but if you scroll down there is a bunch of games from their Silver Line for $5.
Kingdoms is supposed to be a good game, its by Reiner Knizia anything he makes is probably worth $5. Also Minotaur Lords and Scarab Lords are supposed to be good. I want King's Gate as well. On the list I have only played Atlanteon and its okay it was worth the $5 I paid at GenCon.
http://www.fantasyflightgames.com/5dsale.html
The FFG Fantastic Holiday Sale begins on November 21st and runs until Midnight on the night of Monday, December 4th!