1. XCOM: Enemy Unknown XCOM came out in October, so it's maybe the biggest ticket item most deeply on sale with a tidy third slashed from its price. If you like chess, you'd probably like XCOM — provided you can put up with some punishment. Defending the world from a fierce army of alien invaders is costly, and creates a lot of tough decisions. Currently $33.49 on Steam

2. Walking Dead Created by Telltales Games, the developers Sam & Max and Tales of Monkey Island, The Walking Dead turns an action and adventure game into a bleak narrative about a zombie plague. What's more, you can never lower your guard: the game will throw life-or-death decisions at you at any time. Currently $12.49 on Steam

3. Borderlands 2 DVICE approved, chances are you're already playing Borderlands 2. If not, there has never been a better time — the game is already bigger and better, with two sizable chunks of DLC that have you battling pirates on Star Wars-style floating skiffs and duking it out gladitorial arenas. Borderlands 2 is already big, and yet more content-heavy DLC is in the works. Read our review. Currently $44.99 on Steam

4. Endless Space Endless Space lives up to its name by giving you a galaxy full of detailed planetary star systems to conquer. While it has no formal plot, the game's different races are oddly well done, with interesting hooks such as an eccentric and rich megalomaniac who founded an empire of clones of himself, or a race of space amoebas. The game is made by a small studio that regularly works in improvements from community feedback. Currently $14.99 on Steam

5. Krater Krater is a more light-hearted approach to a gritty post-apocalypse, filling a harsh world with colorful, varied mutants. It's a work in progress, and the small developer behind it is adding more to the game all the time with player input. Currently $5.09 on Steam

6. Dishonored Dishonored already scores high marks with us for how rich its steampunk world feels, and will appeal to anyone who likes a little flexibility in how a game plays. You could try to cut your way through your foes, for instance, or sneak around them, and kill without a soul knowing. Read our review. Currently $44.99 on Steam

7. Sins of a Solar Empire: Rebellion Sins of a Solar Empire allows you to command an interplanetary empire like Endless Space, but does it in real-time with more emphasis on big fleets going at it with space guns and lasers. The venerable series is now on its fourth iteration, and it's added the biggest ship in any update: powerful titan-class vessels that can take on whole fleets. Currently $19.99 on Steam

8. The Fallouts While they look a little old now that Skyrim has raised Bethesda's bar, Fallout 3 and Fallout: New Vegas both come in complete packages that include all of their respective DLC. Either one will last you dozens of hours. Currently $11.99 and $17.99 on Steam

9. EVE Online: Inferno EVE Online is hard to recommend because it a) requires a monthly subscription (which is effectively slashed in half right now) and b) it can be pretty hellishly hard. That said, if the idea of sitting on the bridge of a proper starship keeps you up at night, EVE is one of the best ways to do that, and it looks gorgeous. EVE's ship designs and universe alone is worth the cover charge, even if just for a peek. Or, Plan B: just watch its amazing trailers. Currently $9.99 on Steam

10. Deus Ex: Human Revolution If you were interested in this story we ran, you'll like the world in Deus Ex. Like Dishonored (which was developed by a veteran of the Deus Ex series, in fact), Human Revolution encourages players to play it in a variety of different ways. The game's fiction is thoughtful in how it approaches a not-too-unreal-sounding turning for humanity, which the lines between man and machine are starting to blur. Currently $2.49 on Steam

One To Watch: FTL: Faster Than Light FTL is small and mighty and worth every penny it is now, but it's not on sale, so in the spirit of this list we're putting it on watch. Still: any budding starship captains, apply within. Read our review. Currently $9.99 on Steam

One To Watch: Natural Selection 2 Natural Selection 2 pits a team of hardy space marines against a gaggle of ferocious aliens, but with a twist. The game features a command and conquer element, where a commander tells the team how to focus its efforts. The commander also upgrades the team's base, which allows for better technology in the field, which essentially culminates in a war machine vs. beast scenario as good as Ripley in her power loader fighting the Queen. Currently $24.99 on Steam

Honorable Mention: PlanetSide 2 PlanetSide 2 just went live, and if you're looking to simulate the warzone of the future, it's hard to do better. The game features huge squads of players duking it out across battlezones that are digital square miles large. The best part? It's free to play. Check it out for free on Steam.