The nosy Temerian soldier who interrupts Geralt's and Triss' morning proclivities and who takes his sweet time vacating their tent while ogling the Sorceress.
Geralt: Stupid war. It could have been such a beautiful morning.
While besieging La Valette Castle in the prologue, go ahead and cast the Aard sign on one of the defenders near the edge of the parapet... Go on.
The same goes for defending Vergen on the Iorveth path.
The fantastic inversion of the Main page's image quote. This Troper was choking with laughter.
Vernon Roche: What would you do if you escaped?
Geralt of Rivia: I'd go have a beer.
Once Roche and Iorveth first meet in the forests on Flotsam, Iorveth greets Roche with a long-winded, scornful speech in which he lists several of Roche's accomplishments, titles and says how he has spent the past few years setting up traps and devising plans as he eagerly awaited for the day when the Special Forces Commander would wander into his forest. Unimpressed, Roche bluntly responds with —
Vernon: Iorveth, a regular son of a whore!
Extra poignancy is revealed later when you learn that "son of a whore" has a particularly stinging personal edge for Roche. He was actually giving Iorveth an insult he considers the worst when used against himself.
The aftermath of the drinking in the 'Hungover' quest.
Especially if you ask Triss for help - when Geralt says she can stop laughing about it, she gasps between bouts of laughter: "No, I really can't!"
While in Vergen (on Iorveth's path), you have to play dice against a dwarf to win a quest-related item. After winning twice (gaining a sword and the quest-item), he says "I'm not playing anymore!" in a tone that makes it sound like he's on the verge of tears.
From the DLC, there's a quest at Vergen called 'A Sackful of Fluff', where a man named Elthon contracts Geralt to collect Harpy Feathers for a client. Then you see just what "his client" wanted the feathers for. The completely deadpan conversation afterward is just icing on the cake.
For bonus points, you get Elthon's Trophy from completing that quest. All of Geralt's cynical comments and philosophical insights become a little surreal when he's got the Trophy stuck on his nose.
A combined Funny and Awesome moment - when first meeting with the Scoi'atel, Geralt demonstrates his prowess by mentioning that there are four elves hiding in a tree, and one of them is either on Fisstech or has a cold due to a wheeze. The expression on the elf leader's face is priceless.
In Chapter II of Roche's path, if you opt to get information out of the Visionary by 'converting' to his religion. To do so, you have to imbibe a potion of his own make in front of a shrine and have a special vision. Said vision involves giant phallic 'mushrooms' appearing in the forest, alongside an enormous chicken. Made all the more side-splitting in that reporting this back to the Visionary is exactly what he wanted to hear!
One in the beginning of chapter II (Iorveth's path) and related to the main plot, the sorceress Phillipa needs an artifact with an ungodly amount of power. She suggested one of the legendary Twenty Rings of Power, leading to Iorveth snidely quoting from the famous ring verse "one ring to bring them all and in the darkness bind them." Then Geralt envisions himself running barefoot up a volcano.
Another one in Vergen, when Geralt chats to a sprightly young vendor in the market place:
Spark: Uh, so what does a Witcher do, anyway?
Geralt: We solve problems.
Spark: Oh? I have a problem with my boyfriend...
Geralt: Did you find his entrails sprawled on the porch and his head a few paces away? Because those are the types of problem we solve.
Another one from Vergen, when Philippa gives Saskia the antidote to the poison, finishing with a kiss through a Rose of Remembrance petal, we hear the town Elder, Cecil, say "Now that's my favorite kind of magic - lesbomancy!"
As Roche starts his interrogation of shackled Geralt, he offers his hand to shake. The "very funny" dialogue option leads to...
The interrogation gets even funnier if you prove to be uncooperative.
Geralt: What do you want from me, Roche? I already told you it wasn't me. On top of that, I don't know who's behind it, and frankly, I don't really give a damn. Could've been anyone as I see it. King Demavend, even.
Upon reaching Flotsam, go talk to Triss in the tavern. Asking her how she's been yields a Deadpan Snarker list of what it's been like stuck on the ship with the rest of the all-male crew.
Triss: I can burp the Nilfgaardian emperor's title without reaching for beer and I've discovered that Shorty's name has nothing to do with his manhood.
When Philippa Eilhart mentions that the customary title for her apprentice Cynthia is "Leashed Sorceress", Geralt gives a hilariously deadpan response: "do you also use a muzzle?" Philippa gets offended and explains the completely innocuous background behind the term. Later, you end up walking in on the two of them in the middle of a BDSM spanking session.
Roche gets a small one that doubles as a Crowning Moment of Awesome near the end of Chapter II on his path. As he and Geralt charge through Vergen, killing every Kaedweni soldier in sight, he runs across a bridge... which falls out under him. Roche curses as he tumbles, rolls as he hits the ground, and without missing a beat, takes a Kaedweni soldier down with a tripartite set of punches and kicks as he gets up.
Upon first arriving in Vergen with Iorveth and meeting Yarpen Zigrin, the conversation includes this:
Yarpen: Well, Saskia went with prince Penis... uh, rather... Stennis to negotiate with Henselt.
After succeeding in locating a succubus' lair, who has allegedly been killing the men of Vergen, Dandelion faces a dilemma: