The Christmas day list of things for the Steam sale is as good as any day that's come so far. Let's get straight to the deals:
Fallout 3: $7.49 - Years ago, when this game first came out, I sank over 400 hours into it. I don't think I've spent that kind of time with any other game, ever. The expansions make it better yet, particularly Broken Steel. Though it's a pretty radical shift in UI from the original Fallout games, it is absolutely a worthy successor to that series. It's also just a fantastic game all on its own, and very much worth playing.
Batman: Arkham Asylum: $4.99 - The original Rocksteady studios Batman game demonstrated that yes, in fact superhero video games can be good. Great, in fact. They got the voice actors for The Joker and Batman (Mark Hamill and Kevin Conroy, respectively) from the excellent Batman: The Animated Series to reprise their roles, and wrote the game much like the series, but not for kids. The result is something incredible. Well worth playing.
Atom Zombie Smasher: $2.49 - A kind of unique quasi-tower defense game centered around pulling people out of zombie infestation zones. The graphics are nothing special, but the gameplay is very solid. It's definitely worth grabbing for this price, or pick up the bundle that includes it.
Overlord Games: $4.99 for the complete pack - I'm starting to sound like a broken record as this stuff keeps going on sale again and again, but this series really is fantastic. Rhianna Pratchett (Terry Pratchett's daughter) was involved in the writing, so the games are genuinely funny. The gameplay is good, too, though I'd recommend playing Overlord 2 with the aid of a cotroller.
What I'm getting: I picked up the X mega set thingy. The space combat/exploration/trade genre is one that's always sounded cool to me. I've given it a try various times before, but it never took. We'll see if this one scratches the itch.