Too many reasons why not to go Skyrim in my honest opinion. From the top of my head, it just dumbed down way too many aspects such as getting rid of parkour (and Athletics and Acrobatics), the menus, dialogue and choices, cookie cutter talent trees and investing in real estate. There was no strategy to combat and magic was an absolute joke, as Fire was the only thing that had major results. Add to this technical issues like freezing (especially at the start of the game), missing textures and more invisible walls than you can shake a stick at, and you've got one of my least favourable RPG experiences.
It did have its good points though. The story was very well told, but the characters and factions had zero depth or meaning. The character models, while muddy and grey were quite nice to look at and the voices were spectacular. The environments when they weren't just rock, snow and tree were great and the quest model was superb.
I think most of the reason why I'm so bitter about the game is not the product itself, but how players and developers treat it like a standard RPG and not the Elder Scrolls. For me it just wasn't very memorable and because of that, most of my mental recollections of the game are bitter.