I think that Skyrim is one of the best games I've ever played. Ever. At least in the top ten list. That said, there are a few things that, while not game-ruining for me, are somewhat immersion-breaking. Example:

I'm sneaking around in a cave with my enchanted bow of soul trap. I peer around a corner and see two bandits, one sitting at a table with her back to me and another at a cooking pot over a fire. For whatever reason, I thought that assassinating the one at the table was a better first move, so I shot at her first.

One arrow, one kill for the first attack. Then, a stream of purple energy flows from her corpse to my bow with a crackling energy sound, similar to a thunderclap, as it does it's soul snare. The other bandit says something similar to "What was that?!"

I hide around the corner, dagger ready to ambush him. I can hear him moving around and he says something to the effect of "Show yourself!" Then, maybe 20 seconds later, I hear him sheath his sword and say "Guess I was imagining things." I like to imagine that he keeps a diary and, had I not shot him next, he would have made an entry that evening:

"Dear Diary - I finally cooked that cabbage stew I was looking to make. Man, it's good. I mean, I've eaten cabbage soup before, but oh man is this good."

"Oh, and I have sad news. Janhaadulemed died today, maybe of natural causes. I say maybe because I found an arrow stuck in the back of her head, but she may have fallen on it after sudden death."