Here's couble legendary ones I can remember even, err after long period un-sleepyness...
Shadowrun 3rd ed: My Troll Shark Shaman, at the moment 4rd level initiative, and his mates get involved to bar fight in small bar in Alaska, and Slaughta, my shaman was the one who started it, ofcoarse. So, Slaughta gets iniative, naturally as only chahracter with move-by-wire would go faster, and GM ask what will I do. I simply say "Mä teen Raipat!" "I'll do Raippa's!" ( One of the other players, was banned earlier from hangout bar for hitting bar stool to some idiot's head ) Everybody laugh their lungs out, including Raippa...
Before LARP called Örkkikorpi II/Orcwilderness II, as orc players are putting so make-up in cparking lot. I'm painting big warpaint to my frriend's, Henkka, back:
Henkka: What are you painting?
Me: You promased that I can paint anythink I want.
Henkka: What the f**k are you painting?
Me: Weeell, it's holy symbol...
Henkka: (broudly & loud) Well, it is holy symbol of Spider Goddess!!!
Others: laughing out loud!!!
Me: Well, it have 8 legs or something... (while trying to stop laughing...)
Henkka: Teemu, PERKELE! (after someone told that picture in his back is meter long vulva...)