Portal comes in the Orange Box combo disk of three Half Life games, Portal, and Team Fortress 2.

In Portal you play as a human/robot thingy that uses a portal gun to complete various tests for GLaDOS, a robot in control of Aperture Science. As with many games I like, it's full of puzzles, and I'm looking forward to the challenge modes, these include the advanced mode, and various other things such as completing levels as fast as possible or with as few portals as possible. It's a great problem solving game I recommend for anyone, and of course, the orange box does own.