One of the best deals I have ever bought, with 5 of Valves best games one one disk you can't go wrong with buying it.
Portal
This is a game that took me by complete surprise, why you may ask. First it's a game that relies heavily on puzzles, not just in a few parts but all the way through. But it does them so well, not one did it get frustrating and it supplied a fun filed few hours. You'll have a tool or gun called the portal gun, this is what you will get through the game with. The game in writing is really hard to explain, the portal gun you use can make two portals you can go through. Thus getting you from point a to point B, it really sounds easy but at times you'll have to think about what decision you going to use.
There are only two people in the game one who you play as Chell, and a CLaDOS (Genetic Lifeform and Disk Operating System). Neither really add much to the game, but towards the end it takes a nice little twist which makes it a lot better. And the end will probably come somewhat fast, according how good you are with figuring things out. The shortness of the game is the really only complaint with the game, as it ends way to fast and leaves you wanting more. But in the end you'll be left with an addicting little FPS puzzle game that you'll play through several times.
Team Fortress 2
Is an online game only, you want find any single player mode while playing this. There's two different teams you play as either red or blue. Both teams offer the same kinds of things, which are nine different classes you can play as. The classes are put into three different roles offense, defense, and support roles with three characters put into each one. Offense offers soldier, pyro, and scout, defense offers engineer, demoman, and the heavy, while supporting roles offer spy, medic, and sniper. Each class has there own weakness and strong point that will help the team out. Which one you like is mostly based on how you like to play, but pay attention to what classes you team has already. This is a heavy team based game, therefore you don't want your team filled with the same class. It can be really hard to win if your team isn't organized or tries to go Rambo, making the game less fun.
Each class also has a set of weapons it starts with the primary, secondary, and a melee weapon. The graphics aren't like other games, they look like something you would see in a cartoon. Which at first might sound like they look bad, but it actually works for the game and looks great. One of the biggest problems with the game is on the 360 the community has went down as far as how many people play it. There still is a small amount of people who still play it, and the ones who do are greatly skilled at it. Prepare to not do so well until you get the hang of it. But one of the great things about the community is if you ask them for tips most will show you the ropes, and get you up to speed pretty quick.
Half Life Series
One of the most acclaimed First Person Shooter series ever to hit shelves is included in this disk. Not just one but three, the first Half Life 2 is a full length game. While HL2: Episode 1 and 2 are something like an expansion pack. In these game you'll be playing as an iconic silent protagonist named Gordon Freeman. You'll be transporting through a lot of different areas, while having the help of others along the way. You'll have all types of different weapons along the way, you will start out with only one and gradually pick more along you journey. Between the three game the controls don't really change at all with everything being the same, although most people would say this needs to change it works really well. The controls are very smooth, and the game still provides the play with health packs unlike most modern games.
The story is something that is really complicated, and through out the series there are a lot of plot holes. If you haven't played the first game you shouldn't worry to much. The direction between the first and these three are a big difference in setting and story. But at the same time you'll still more than likely get confused at things going on, are who a mysterious character is. Like the gameplay you'll notice more than one thing that hasn't changed between these games. The graphics for instance is the same in all three, comparing to games of now they are a big downgrade. But if graphics don't matter then it shouldn't be a problem, besides each character is detailed very well, along side all of the environments. The soundtrack may seem weird at first, it's usually something you would probably hear at a club.
Episode 1 and 2 are great expansions to Half Life 2, but with so many other expansions out there they are really short. If your really good at the games you can get through Episode 1 really fast, it's over before it even starts really. Episode 2 isn't as short but you'll probably find your self going through it pretty fast as well. One of the best things about the series is the pace the game take, it's pretty fast but that also includes how your pace is and what difficulty your playing on.
The Orange Box is and incredible deal and has some of the best games you can play. All of these games are ones you'll spend hours on and find your self going back to over and over again. Not to mention it's at a really good price at the moment and is just going to keep going down. That being said you can't really go wrong with a package like this.