Fear not if you missed out on Black Friday or Cyber Monday--HinterWelt Enterprises has got you covered for the gamer on your list (even if that gamer is you!). The Happy Holidays Sale offers 20% off all their in-print titles across the board.
I've mentioned Squirrel Attack! here before, but HinterWelt has done some other really cool books as well. For sci-fi that is character-centered but not necessarily human-centered (humans are pretty much cockroaches in this instance), check out Nebuleon Revised. For the single-best True20 setting out there, try Roma Imperious (also available in Iridium flavor). An alternate Roman timeline where the Empire doesn't crumble in the 4th and 5th centuries, Roma Imperious was nominated for Best Setting when I was an ENnies judge--and as I recall, is one of the few products all the judges were pretty high on. Oh, and a free pdf is included with the print copy.
One of the great things about HinterWelt's books is how easy they make it to swap out the system by keeping it compartmentalized from the setting.
The sale apparently runs through January 2, 2010, so grab something while the getting's good!