The Half-Life series is a fan favourite for a ton of reasons, but the main one is that its universe and story are so strong. Strong enough, even, to be re-told in under seven minutes using...paper.
Below is the first Half-Life, re-enacted using little paper men, and told in 2:14. Below that is Half-Life 2, which thanks to its beefier plot runs to 3:57.
Both clips are the work of Stepan Yurov. He may tell a shorter story than Valve's epic shooter series (and include more Pac-Man cameos), but it's all the more charming because of it.
[Thanks Fish!]