To start, this thread is not intended to bash the game. The impressiveness of the outdoors is the most immersive I've ever encountered in any game, ever.
The dungeons (i.e. caves, temples, etc) are equally as amazing.
The problem is when you start encountering and interacting with NPC's.
Example - I got a quest to steal something from someone's house. I wait until nightfall and pick the lock whilst no one was watching. I enter the house, at 2am, and everyone is awake and wandering aimlessly. People start acting belligerently towards me (as expected), and the guy who's item I was supposed to steal comes up to me as if to lop off my head.
Instead, I start a pleasant conversation with him, and wind up with a quest to do something for him. After hitting Tab to leave the dialogue, everyone, including him, go back to threatening me again.
2nd Example - Wandering around in the cold, I stumble on a camp. Turned out to the Stormcloaks, and at this point I joined neither side. Wishing to test out my Sneak perks, I stay pretty far, snuggle behind a rock, and exposing myself only enough to take a shot, I calmly picked one of them off (one shot kill). Of course everyone in the camp turns 'red', but I hunker down and within a few seconds I'm Hidden again and the camp resumes it's aimless activities as if nothing happened. So what the heck, I pick off all the other visible soldiers, one by one. No problem.
I enter the camp and see someone calmly working on a bench. Dead bodies everywhere, he's oblivious. So I backstab him and he howls, screams, whatever. I go in a tent (three soldiers are still asleep somehow), mutter 'what the heck' again, and backstab one of them, expecting the other two to wake up and attack.
Nope. So I backstab another. The third soldier is now sitting up (awake). I try to pickpocket him, but the message says "he caught you". So I kill him too.
I enter another tent, and there's a named NPC. I try to kill him, but of course I can't.
I seriously hope they fix this kind of behavior (or lack thereof) but I sense this is the essence of the "AI" and will remain wacky.