The one I found the most annoying, to avoid spoilers I'll describe as the one where you'll hear "Yrden, trap it with Yrden!" a whole lot.
God, don't remind me. The very first time I played the game I think it took almost 30 tries to beat that fight. I think they nerfed it a bit with the enhanced edition, because my most recent playthrough was nowhere near that bad.
I'll be here to eat my words but it won't come to that. May 19 2015 will mark the launch of the best RPG ever.
Honestly I'm right there with you. I've been burned before and I'm a little afraid to get my hopes this high for any game, but I probably have more faith in CDPR than any other game studio at the moment.