I love the sound effects in this game, save a few.
Nirnroot is very annoying, as well as bears and all associated heart attacks they give me, but one sound I despise is Chaurus and Chaurus Hunters. Not only do the things themselves disgust me, but the noises... Ugh, especially when one bursts from it's cocoon... you can just kill me now.
I honestly love the dragon's voices. Not only when you are talking to them, but also just when they shout when you are in battle with them.
I also love the satisfying sound when you bash a skeleton to bits, and it's bones go flying. That sound is just... so... satisfying.
The thud of an arrow meeting it's mark is very satisfying too. Especially if it's an impossible shot, like I have managed to pull of many of on my huntress - she is tracking a deer, lines up the shot, hits, the thing is down 3/4 of it's health, so I draw again, and the arrow flies through the leaves and thick brush and I hear the light thud of the arrow, and the deer collapses... fantastic.