I've never played a Half-Life game before this and I gotta say I regret not playing one!
Half-Life 2, Ep.1, Ep.2:
I went into Half-Life 2 with no knowledge of the story but I instantly was made aware of it. The scripting was awesome and the way they tell you the story is great. The characters facial expressions are amazing for a game originally made in 2004. The game obviously went under some enhancements when it was ported over to the 360 but I'm pretty sure that didn't change. The graphics were great. The textures were typical for a 360 game but the water looked really good. The only problem with them was when the game loads after a checkpoint it takes a little while and once it does load it is kinda slow for a few seconds. The controls are very tight when you're walking around, but when you get into a vehicle the controls are very sensitive and loose. The only problem with that however is in Episode 2 when you get the car. The car's steering is way too sensitive. The sound was great. When you get to an enemy-filled area, the music changes to a faster-paced and darker track. The overall gameplay is great due to physics which are amazing. The physics are very important for the famous gravity gun in Half-Life. If you are considering The Orange Box because of Half-Life then definitely get it. If you are considering it for Portal or Team Fortress 2 then Half-Life is a nice bonus.
Portal
Probably the most popular game in The Orange Box, and YouTube due to the Still Alive credits song, Portal is an instant classic. The only problem I have with Portal is that it seems very short. The game's story gets told progressively through the game by the sarcastic and amusing GLaDOS (the AI robot that watches you and talks to you throughout the whole game). The graphics are really good for a game that seems pretty simple and basic. The physics are pretty good and are definitely the same engine that Half-Life uses. Once again the loading gets plagued by slow load times and glitchy parts after it loads. The sound is good because GLaDOS' voice echoes around when she talks. Overall this game would be a great standalone edition to the Xbox Live Arcade if it were released by itself.
Team Fortress 2
This is the game I spent the least amount of time on. It wasn't cause I didn't like it, it was because I didn't have much time and when I did play it I couldn't ever find anyone in a ranked game and I wanted to see what you get for stats when you play ranked. I did get to play with some friends (pill92 I'm looking at you) but other than that it wasn't that great of an online experience when getting on. Although, the few times I did play online I had a lot of fun. The controls are good, although they take a little getting used to. The graphics are pretty good. I like the comic look to everything. The sound is pretty good. The taunts you can do with certain character classes are really funny, too. The whole idea of picking a certain character class is great. The maps are really fun to run around on and the different types of weapons ranging from a baseball bat to a portable turret are always fun to mess around with. Overall this is a game where it could be sold as it's own 360 game (only not for the full $60).
Overall here are the stats:
Graphics: 9.0 (due to load times and glitches)
Gameplay: 9.5
Sound: 9.5
Physics: 8.5 (also a culprit in load times)
Score: 9.0/10