Hakha and Rico's traded snarks and insults can be quite funny.
When Hakha states that the earth fleet is soon to arrive, Rico asks "How do you know that shit ?", he responds:
Hakha: I'm the a spy, its my job
Rico: So the mighty brain agrees with the grunt, that's a first.
Hakha: Even a monkey could write Shakespeare if given enough time.
Rico: What the hell's a Shakespeare ?
Luger: Hakha, do you know when the earth fleet will arive ?
Hakha: I don't claim to know everything.
Rico: The way you act, its like you know my mothers bra size.
Hakha: Well I'm guessing...Large.
When the Templar and his group become unconscious after nearly escaping their boats destruction, we see Templar lying on top of Luger, close to her breasts. And after they wake up:
Templar: Well this is familiar
Luger: What ? You falling asleep on top of me ? (then shoves him away)
Templar: (Disappointed) Yeah...
Garza's witty and sarcastic comments can be hilarious. It no wonder why he's quite the fan favorite.
After surviving a Helghast ambush and reuniting with Natko:
Natko: "You sure took your sweet time gettin' here! What'd ya do, stop off and make lunch?"
Garza: "Yeah. My mom packed me a lunchbox with a nice ham sandwich before I left. DE-LICOUS!"
His saying on the helghan insects
Garza: I dunno, you could think of them as useful parts of the natural order rather than great big, creepy, corpse nibbling...Okay, your right. Fuck that.
During Radec's interrogation:
Radec: I'm not a very patient man. Do you understand why I'm here ?
Garza: I guess your mom got drunk with the guys one night...
Radec: (Enraged) You are next !
When Sev and company try to open a door leading to radec's office, Garza states that to open it would require finesse. When the door does open, it reveals a secondary door. Rico then promptly shoots the lock and kicks it open.
Rico: Finesse my ass.
Rico apologizes to Sev for shooting Visari and getting him threatened with a courtmartial.
Sev: It's ok, I wanted to shoot him too.
Rico: But you didn't.
Sev: That's because I'm not a jackass.
After Sev lands safely after nearly avoiding a crash landing from his malfunctioning jetpack, he is then hit by a tidal wave caused by the destroyed base collapsing into the water. Sev can only react with an annoyed "Really?"
Sev taking a Helghast radio and affecting a British accent when the Helghast comms officer asks for a response.
During Stahl's speech to the Helghast people, he says the word "fucking". When you think about it, Stahl just swore on national television.
Orlock's smug look when the Helghast High Council names him as Visari's successor.
Killzone: Shadow Fall
In a sort of black comedy, should Kellan fail to detonate the EMP bomb whilst he's on the train, he is then casually shot to death by the Helghast trooper guarding it. The trooper then calmly tells the passengers to not mind that theres a dead body besides them.