Portal is a new game that is part of Valve's Orange Box release. Orange Box includes some great games, including Half-life 2, Episodes 1 & 2, Team Fortress 2, and Portal. I think Half-Life 2 is OK, but not my cup of tea.
Team Fortress 2 is fantastic, adn I have spent many hours playing since it's release. Absolutely great stuff that breaks the FPS out of the traditional military look. But the real gem is Portal.
Portal a whole new kind of game. Based on the idea that you can create portals between two locations that not allow you to pass yourself and object through, but that momentum passes through as well. Doesn't make sense? Watch the trailer here.
Fun gameplay with no killing. Old FPS skillz don't apply in this game that is more about planning and less about twitch. The gameplay requires lateral and innovative thinking to succeed. It's a complex puzzle game, but truly addicting. I finished the campaign game in two sittings, but some finish it in a single 4-5 hour sitting.
There are more challenging levels after completing the campaign and I'm sure the mod community will be coming up with many great levels to try.
Portal (and Steam, the Valve game delivery system) are PC only. But Mac People, that is the reason Steve has bestowed you with Boot Camp. Between Portal and Team Fortress 2, you won't be disappointed.
Possibly the best part of the game is the humor of the voice that guides you along the way. By the end of the game, I was pausing just to hear all the talk. And the final song by Jonathan Coulton is hilarious.
Of course, item #1 on my Christmas wish list will be a plush Weight Companion Cube...
Finally, a good use for facebook: