Wow, now that they have Steam for Mac, maybe I ought to dig out my old PC copy of Half-Life and enter the serial and see what it gives me access too. Not sure how many of any of those game have Mac counterparts, probably none, I know HL doesn't. I guess the serial of my PC version of Half-Life 2 would give me HL2 for Mac, but since I have it on the 360 I'd rather just play it there.

Wow, if they made an HD port of the first Half-Life complete with expansions for Xbox Arcade, I'd wet my pants right now. That would be so awesome... same for System Shock 2.