Well, to be fair, Shadowstrider has remarked that the Oblivion AI was actually completing quests and closing Oblivion gates on its own. I think that's pretty cool. Too bad Bethesda simply nerfed the AI so it wouldn't compete with the player rather than trying to harness that ability.
Wasn't in Wizardry 7 where the AI actually had NPCs that were competing with the player on the main quest, and if the player took too long to find Map pieces, the AI npcs woudl often get there first?
Imagine how much more interesting looking for Nirnroots would be if there was other npcs gathering them as well, and if you took too long, oh well, no prizes for you.
Instead we get:
Hi!
Good Day.
I saw a mudcrab today.
Annoying creatures.
Their claws are sharp through.
Indeed!
*clears throat*
Goodbye.
I've read reports that Radiant AI, at some point during development, also featured NPCs blatantly robbing each other, then attacking the offender. Instances where one NPC wanted an item, took it from somewhere, either by force or just picking it up. The owner would look for his item, find the other NPC had it, and pick a fight,. After a while, you start wondering where your shopkeepers went!