I've always adored the audio design of the Half-Life series and especially the really creepy way that the Combine soldiers speak. This video just gives you the radio chatter of Freeman storming the beach with his Antlion soldiers and even intersperses the randomly-generated dialogue to simulate their Combine teams being taken out by him one after another.
There's so much characterization built into this shit, too. You can hear the soldiers panicking as they get overrun and calling for help.
In this other one you can hear the Overwatch as well, and at one point the commander incredulously reports that Freeman is controlling antlions https://youtube.com/watch?v=YJZiIjyeT78&feature=shares
It's one of my favorite things about the game. The soldiers have their own particular jargon that is only ever there in the background, I don't think any character ever comments on it or explains it. It makes the world feel more alive and like you're one single person in this grand situation.
They change the jargon throughout the game to reflect the situations too, like the player goes from being a "staph infection" to "Anticitizen" then "Anticitizen One." Most of the time they use medical terms to refer to situations, but they have other terms too. Echo means a soldier, swords/daggers refer to their weapons. Sometimes you'll hear them say "go sharp" to mean unholster weapons. When you kill a bunch of them, they refer to it as an outbreak, and Overwatch tells them to coagulate, clamp, and cauterize to mean send reinforcements.
I also remember they have their own version of the NATO phonetic alphabet, but it's different, like Apex is A and Black is B.
The Overwatch Voice also has a ton of cool dialogue with this jargon. The part where it lists out your crimes and charges you is just great, "Divisive Sociocidal Counter-Obeyance", "Disassociation from the Civic Populace".
Overall I feel like this is a much cooler implementation of the newspeak concept than whatever Orwell did, the whole using of medical analogies is really interesting, with the Combine seemingly viewing society as an organism of sorts - disobedience is a literal social disease, and the parts of the populace affected by it have to be "sterilized" and "amputated"