I cannot fault The Orange Box. For $100 NZ, you get 5 games, many of which have averaged above 90% in many gaming reviewers. It combines the old: Half-Life 2, which I think does a good job of portraying an Orwellian future, while still offering plenty of good action and classic HL style puzzles, and Half-Life 2: Episode One, which, in my opinion, is the weakest link in the box, but still rates highly in my books. Next you have the new: Half-Life 2: Episode 2, which takes everything in Half-Life 2, and perfects it. The most enjoyable 6 hours of gameplay in my life. Next is Portal, which is challenging, original and genuinely funny. Its worth playing through the game just for the ending credits. Lastly, Team Fortress 2. Normally, I'm not a big fan of online shooters, but I make an exception for this. Normally devoting my time to single player games, In the short time I've had it, I've put in 10 hours of gameplay. Hilarious, new, but still familiar to Team Fortress Classic veterans, this game is an instant classic.
I do, however, have a few minor gripes with The Orange Box, which do not apply to casual gamers. A big fan of mods, I was disappointed to see that the Orange Source version is not supported by the SDK. This may seem a minor gripe, one that will likely be fixed in a patch, but it hinders mapmakers. Also, the decision to not include Half-Life 2:Deathmatch, means that The Orange Box cannot be used to play a wide spectrum of high-quality mods available.
For $100, you get about 30–40 hours of high-quality single player gameplay, and a high-quality online shooter. Games of this quality available for $20 a game? How can you not refuse that?