A bit of black humor in the sixth episode, when Colbert's Humvee is driving past a severed head lying in the road. He tells Person to avoid driving over it, and he does so...only to have the Humvee drive over the corpse the head was attached to. Colbert's exasperated "You can't fucking win here." takes the moment from morbid to darkly hilarious.
There's a lot of background commentary from the Marines, particularly radio traffic, that is hilarious. For example, in the sixth episode, there's a large crash in the background, followed by someone yelling that Manimal dropped a box of grenades, followed by someone else adding that "This is why we can't have nice things!"
In the very first episode, while Person is asking Fick for a sitrep not on their actual status but on whether reports of J. Lo being dead are true, you can hear a couple of marines in the background:
Pretty much anytime the Marines start off-key singing.
Especially when Ray's singing 'Tainted Love' and he's trying to get Colbert to do the beats. Eventually, Colbert does so. It's hilarious.
Ray tends to do this a lot across Iraq, even when the company officers are trying to hold a meeting not two feet away.
Their personalized versions of "Boyz in the Hood" and "Loving You".
"You killed a lot of sand. The sand was... very evil." Along with the rest of that conversation, but that was a highlight.
To elaborate: The company settles down for the night in the field. Some Marines posted on watch observe an apparently moving column of lights off in the distance. Given that they have intel saying an Iraqi tank formation is not far away, this is an obviously worrying development, so an air strike gets called in. Unfortunately, the officer calling it in sent the wrong authorization codes and coordinates, so the attack aircraft get sent to another location and find nothing there. The flight leader macgyvers out what he thinks is the real coordinates while in the air, leads his planes there, and bombard that patch of ground—again, an empty field. Come morning, this string of errors becomes more and more obvious to everyone; Colbert, who had correctly judged in the night that the men on watch were merely hallucinating that the lights (from a distant village) were moving after staring intently at them for too long, makes fun of these events in conversation, culminating with the above quote.
Sgt. Major Sixta laying into a group of First Recon Marines who are catcalling at a female Marine sitting guard on a truck nearby:
"Belays that, Devil Dog! You's a'squealin' like a bunch of buttfucked Vassar bitches! Unfuck yourselves! We're gonna suffer the spectacle of WM with a bunch of horny Devil Dogs trailing her stern! Get y'selves squared up here! [turns to Manimal] Corporal. You're inappropriatin' your chemical filtration device by attempting fornication with! Jesus, do I need to tell you to not desecrate your mask with perversions? Where the fuck are your helmets?!"
Ray getting out of the humvee and, while bullets fly all around him:
Ray: Lilley, what the fuck! Would you please, BACK THE FUCK UP.
Ray talking about how he's going to make cookies with the things he's been hoarding, managing to sound like a little kid.
"You know what happens when you leave the Marines? You get your brains back." Thus spake Person.
Ray calls Brad a disowned individual because Brad was given in adoption. Colbert slaps him back sharply by pointing out he was raised by an upper-middle class and cultured Jewish family, as opposed to Ray's white-trashy background. Ray's retort is priceless.
Poke coming across Christenson and Q-Tip roasting the animal that Q-Tip caught:
Poke: What is it with you white boys? Leave you alone for ten minutes you go all Lord of the Flies an' shit.
Garza losing his helmet, and Espera's reaction to it:
Garza: Sergeant, I just lost my helmet! (while the Humvee they are in is racing across the desert)
Espera: What do you wanna do, hold a funeral?
Sgt. Major Sixta's reaction to it later.
Early in the first episode, the Marines get letters from some elementary school children. After reading one particularly encouraging letter from a young girl...
Marine: Ooh, I like them braids. (while looking at her picture)
From the book:
Ray: Yeah. When I get back Iím gonna start a gay club. Iíll call it the Menís Room. There will be, like, a big urinal with a two-way mirror everyone pisses against. It will be, like, facing the bar, so when everyoneís drinking there will be, like, these big cocks pissing at them.