I'm not talking about quest or scripting bugs, but things like how the Key Bindings in the UI don't update if you change them (Seriously, I swapped the 'raise/lower weapons' button with 'go third person'.
There was a lot of potential that they didn't capitalize on, and the product just doesn't meet the level of quality that it should have, given that this is a 5 year old game. With that out of the way, the remaster bums me out in a few ways. I love Skyrim, it it probably Game of the Generation for me.
At one point I had nearly a hundred mods adding new content, etc. I've made two or three comprehensive playthroughs with different characters.