
Half-Life 2:
It's the same game I played 2 years ago on the original Xbox. Still good.
Half-Life 2 Episode 1:
Better graphics, too many zombies, not enough cool scenery, too short.
Half-Life 2 Episode 2:
Amazing graphics, good balance of enemies, great environments, great story, cliffanger (and sad) ending.
Portal:
Maybe the most amuzing game I've ever played. Too easy at first, challenges are WAY too hard. If it was twice as long (like more than a 3 hour game) then it would be the best game ever.
Team Fortress 2:
Havent really messed with it. I cannot use server-based online gaming. I'm too party-based spoiled with Halo 2 and 3. I like the art style though and the classes are pretty cool.
Basically, if you own a Xbox 360, you HAVE to buy Orange Box. It's like Halo 3 and Gears of War. You just HAVE to play it.