There's been a couple of times I would fall through hidden spike traps dug out of the field.I wouldn't even be the first one falling through there either. Guards, deer, predators, courier, and stormcloaks have been found in them.
Another cool bit was the story behind Brand-shei, pretty awesome backstory of the war in Marrowind.
I also came across a couple from Cyrodiil who had a lot of bad luck who were complaining all the way.
A challenger approached me about magic in Whiterun, don't know how he got in when Whiterun is closed off to the world unless it's official business. Here's the weird part, I summoned a Frost Atronach to fight him, he did something to cause it to flee, first time I ever saw that. Another time like that would have to be Krosis on Shearpoint who turned my Flame Atronach against me.
Not particularly noteworthy unless you like to play as a very low level character but I've stumbled across some crumbled stone out in the wilderness with a couple of dwarven arrows laid on it like it was an altar.
Yeah, I came across a couple of those with armor or weapons laid carefully on them.
The most awesome thing I ever saw in Skyrim is a battle that was happening like this: I was on Shadowmere in the Pale. I crested a small rise and heard the sounds of a titanic battle. The distant roars of a Dragon, and the great storming stomps of a Giant. Sure enough, the battle I saw was 2 Dragons...1 Blood Dragon, the other I didn't know. Fighting them were 2 Giants and 2 Mammoths. Mixed into this epic battle were 2 wolves and 1 very pissed Cave Bear. It was epic. So epic I just sat and watched it unfold. The sounds coming through my Turtle Beach headset was nothing short of astounding.
If only you could've recorded it. Here are the different kinds of dragons:
I've found many things, often just hidden trap doors to places that you don't see at first glance.
I saw a necromancer reviving chickens so i cast fury and it was a close 1, those chickens are tough!
I saw some hagravens make a briar heart, I found a friendly forsworn camp, an empty mine with a journal about how these 2 people had found nothing for weeks and his partner had disappeared and left him there, then i found the poor guys body in a cave-in surrounded by gold veins, life sucks
I came across that guy practicing on chicken before, he's at one of the standing stones or some landmark I think.
The cave in story reminds me of the two guys at the entrance and closet on the first floor in the Dunwich building in Fallout 3.