Steam is an online platform that lets you download and play over 2,000 video games, from first-person shooters to RPGs, as well as a pretty long list of indie games. You can play on your PC, Mac, mobile device, or even your television, and it has a community of over 40 million gamers. Prices are different depending on the type of game and how new/popular it is, but they're generally about the same as what you'd pay for an Xbox or PlayStation version. They also have a decent list of free games...