If you haven't already played through Portal 2, you should get on that: at least a couple sections are going to continue to pop up as Internet memes over the next five years, and so you probably owe it to yourself to not be totally lost when they do. As far as the game itself goes, the co-op comes highly recommended, though it'll be over long before you want it to be.

Did you know X-COM was on Steam? Do you not already own it? If you don't, take a moment to feel ashamed, and then read on.

Set in an alternate 1998 in which the world is being slowly infiltrated by a sinister group of aliens, X-COM is a tactical turn-based strategy game with a very deep research/production metagame that involves capturing alien technology and adapting it for use in the field. There's a great deal of pressure to advance your bureau's capabilities in this manner before the alien threat overwhelms the world, making for an unforgettable first playthrough (and subsequent playthroughs years later!).

X-COM was a formative experience for me, and is a game I still refer to when discussing contemporary titles. If you missed out the first time around, I heartily recommend addressing your initial error by picking X-COM up now. Besides, it's only five bucks (and probably even less if you're reading this while Steam's having a sale).

One of the quirkier games I've played so far this year, Recettear is a 20+ hour JRPG that can best be described as a combination of equal parts item shop simulation and action-based Diablo clone.

It's funny and well put-together, so if either of the aforementioned composite parts appeal to you, give Recettear a try. Besides, purchasing the game supports independent game localization/development. You like supporting worthy causes, don't you? Just say you do and let's move on.