Fallout 3 seems to, er, fall apart the more I play it. I've since stopped, but back when I devoted twelve hours to it every day, I'd go down to the Anchorage War Memorial at midnight every once in awhile, as there was usually something happening. One time about eight Raiders were holding some kind of initiation, beating up other Raiders and screaming things like "No pain, no gain!" I watched them for a few minutes, but got bored and blew them all up with a grenade. Now that's not that odd, but another time I came around to one of these hazings and about ten seconds after I arrived, one of them threw her own grenade, hit her friend in the face, and gibbed the entire get-together. On several occasions I'd show up to a scorpion fighting a robot.
Every so often after I got near max level, the groups of roving mutants would have a Fat Boy or two, and they always thought it would be an awesome idea to attack the ground directly beneath them. I'd spot them, turn my back for a second to find cover, and all of a sudden the entire place would explode in a blaze of radiation. No experience for me
It kind of irked me that I could never kill the kids when I played my evil characters. If they at least went over to Lamplight that would be cool, but in Megaton, for example, Lucas' kid and whoever that other little girl was would be the only ones left, and they seemed perfectly content to live alone, around the corpses of their dead townspeople. Talk about a dystopia.
Near the end of my time with the game, a jarring percentage of ragdolls would either fly off into space or land on the ground, then start spasming around until the vertices displaced and they looked like stretched out taffy. These didn't ever go away, and by the time I got sick of Fallout 3, my DC was filled with quivering spaghetti monsters. They also constantly produced noise as they interacted with their own hitbox. The sound of slapping flesh and clanking metal around every other corner was probably one of the reasons I quit.
I'm sure everyone's seen a wooden board or other light object floating in water start vibrating, making loud splashing sounds for a minute or two, and then take off into the wild blue yonder like a rocket. Though I guess I was the only one to find a six-foot tricycle in the Red Rocket factory. Thing weighed a ton.