I just tried both of these games today at my friend's house. I only played each game for about half an hour each, but I was really shocked at how much I liked them. I wouldn't think of myself as a fps kind of guy, but these games both hooked me in the few minutes I got to spend with each of them. Call of Duty 4, while a shooter like Halo 3, has such a different feel. The super frantic gameplay of the campaign is wonderful. Nice graphics, and I think they'll be even nicer on my HD tv. Orange Box, specifically Team Fortress 2, was awesome. It's like playing a cartoon. Love the art direction, love the cheeky feel, love the gore. Hilarious, and simply fun. I've actually never played Half Life or HL2, so I'm looking forward to getting to experience that. I don't know much about Portal, but it's my friend's favorite. I know this is kind of "duh" as these are both very popular titles, I just wanted to share my admiration of them. After the utter disappointment of Assassain's Creed, I'm looking forward to getting this when I get my Xbox back from Microsoft.