I can't wait for portal 2.
I played the original game that portal was based on, Narbacular Drop, although I got stuck in that and never finished. You can also see the massive improvement in the original game to portal release.
Narbacular Drop - Wikipedia, the free encyclopedia
After the release of Narbacular Drop, Valve, developers of the Half-Life series, discovered it and hired the entire development team to work for them. The team developed Portal, a spiritual successor to Narbacular Drop, using the same basic concept. In Portal, the player takes the role of a test subject tasked with trying out the "Aperture Science Handheld Portal Device", and along the way discovers that the test facility has been mysteriously abandoned. The main antagonist is a sentient artificial intelligence named GLaDOS, similar to the demon in Narbacular Drop. The game was released on October 10, 2007 on PC, Xbox 360 and PlayStation 3, as part of The Orange Box, to critical and commercial success.
Portal prelude was also a good mod for portal: