I'm a bit late to the party with this particular game but I bought the Orange Box for the Xbox 360, mainly for the first Portal game. The problem is I seem to be a little addicted to Half Life 2
This one improves on the original in every single way. The new search options make it much easier to root out the best levels. A lot of these player levels put the developer levels to shame. So much creativity here with the myriad new tools. I nearly feel like building a level myself.
Nearly
Libertarianism: The belief that out of all the terrible things governments can do, helping people is the absolute worst.