I also liked this scene in Episode 1 where it says:
Rebel: You're Kleiner's daughter, right?
Alyx: No, my dad's Odessa Cubbage.
*kleiner on tv*
Kleiner: ... now would be an excellent time for procreation.
*pause*
Alyx: Uhhh, is Dr. Kleiner really telling people to.... get busy?
(sorry for...
"What is this thing, some kind of weapon?"
"Put that down! It's a prototype!"
*explosions*
"Whoa man, why aren't we using this thing?"
"It's much too unpredictable! Don't let it overcharge!!!"
"What do you mean overchar..."
*more explosions*
Cracked me up when I first heard it. I don't know...