Portal goes out on a cool note, literally, by a great song sung by a character in the game. Fans of the game became instantly infatuated with the catchy tune, and have been making tributes to the song since the games release. This one is especially cool though.
Portal Fan “Thrashbarg” built an old school terminal devoted to playing the song with the images and lyrics digitized to the monitors. While the lyrics themselves are the main source of the spoilers (Which this version doesn’t contain), you will probably get more out of the video if you have played Portal.