Funniest Gaming Moment...

This made me laugh quite a bit, although I warn it may contain spoilers for South Park: The Stick Of Truth

When an NPC got stuck in the door in Postal 2 and started glitching out
Also my favorite dialogue from Saints Row 3

"Do you have any plan or we just shoot all these motherf#!?"

That IS my plan

Works for me."

WHEN I MURDERED ALL THOSE INNOCENT PEOPLE IN THE HITMAN AND GRAND THEFT AUTO GAMES HAHAHAHA!

One of Handsome Jack's lines from Borderlands 2. I can't remember just one cause they're all freaking hilarious, but if I really had to pick, it would be that one: "That's the difference between me, the hero, and you bandits. You also lack money, intelligence, style, a good wardrobe, charm, personal hygiene... I could go on, but I won't...but I could... DIGNITY!!! I forgot dignity." Guy was a real douche. But a funny douche :-p. Oh, I just remembered another one: "Once you've tasted prime rib for free, it's hard to go back to sucking down hamburgers for cash...if you know what I'm talking about. DICKS!!! I''m talking about dicks"

I found this random Assassin's Creed fail on YouTube the other day. It's pretty hilarious IMHO :D
And another one from Assassin's Creed - the rafiq of Damascus. His dialogues were fairly amusing, especially the "I envy you very much, oh, besides the failure and the hatred, yes..." one :D

One of the cut-scenes from Corporate Lifestyle Simulator actually made me laugh out loud. It had been "amusing" up until then, but whatever it was actually was LOLworthy. I can't remember it exactly now, but it wasn't PG-13 :)

I should of been clearer. Not dialogue or in-game scenes, more like that assassins creed fail. Random things that would happen in game, nothing written or programmed by developers.
I used to always laugh when in Wow BC i would be farming at half hp or something and a rogue tries to get the jump on my BM Hunter and i would own them. It become pretty common really. I've had moments in games where i have been in tears from laughing but 100% of the time it was with other people on an FPS or MMO, trying to think of particular times and I cant :(