I've had quite a few, but I'll name just a couple to get us started.

After becoming Thane of Whiterun, I decided to execute Heimskr in front of the Talos Shrine. When the guards came to arrest me, I said "I'm the Thane of Whiterun! Unhanded me!". The guard apologized, and let me go. Whiterun is much more peaceful now.

A foolish Bandit started a fight near a cliff shortly after leaving Ivarstead(I just learned all 3 Words of Power for Unrelenting Force). You can guess what happened next..

after gian the fist performed an unarmed kill animation on me (bashed my skull in), he says "I don't owe you any money do I"

A bandit attacked me while dual wielding a pickaxe and an iron dagger and shouting "I'll carve you into pieces!" at the top of his lungs. I was wearing dragonscale armor at the time and I proceeded to laugh then chop his head off

I had a goat fly at me from out of no where. Just as I was wondering how it did that, I saw a giant heading my way. Guess he wanted that goat. I got his instead.

On the road to Windhelm for the final Legion assault, I came across a random Khajit staring into the wilderness. I dismount and walk up to him. He promptly pulls out a dagger and demands I hand over any valuables.

My character, who is wearing heavily enchanted Wolf armour and is wielding the arms of a Thane of Solitude, tells the thief that he doesn't have anything valuable (presumably while giggling under his breath).

The thief, apparently disappointed, walks off and is promptly hit into the stratosphere by a giant.