I can't remember the name of the play station game... but being woken up by my TV yelling "Fear the Tube of Death" in Spanish while my flatmate wielded a giant cardboard tube in an old play station game.
Back when the Everquest expansion Scars of Velious had just come out (what was that, like 2000? 2001?) I was playing my bard in the Dragon Necropolis. Charmed a phase spider. Hmm... So it has a proc on its bite that teleports its target a small distance, and it proc's frequently. I used it to attack another phase spider, and they were chasing each other all over the place until one triggered a trap that spawned a big skeletal dragon that was more than just me and the druid could handle. Fortunately, we were just had to click the zone-out. We couldn't go back in because of the dumb dragon camping zone-in, though. It was still pretty funny. And that's why I don't charm phase spiders anymore, well, or play MMO's really.
Really funny moment: in the original Half Life, you get this gun (the type is irrelevant) and the scientist who gives it to you tells you to open the holding cages of a bunch of these alien things, and then kill them when they crawl out. I opened the cages, then ran out of the room, sealing the door behind me, and the scientist got horribly torn apart by the aliens.