Skyrim may be more open, but I actually feel TW2 is a more accomplished, creative, polished and ambitious title. Skyrim in many ways is essentially a copy and paste of past games with very little of the fundamentals (that were in dire need of change) actually truly developed. They basically just went for a visual upgrade with some 'cool' additions, namely the dragons.
TW2 on the other hand just feels fresher to me. Dialogue, narrative, consequences of choice, the combat (evades, counters, parries etc all make for a more dynamic and frenetic pace of combat) etc. The general pacing and diversity in the game, all better imo. Skyrim for me never breaks that barrier of believability despite offering so much freedom and (oft false) choice. I think it's the characters themselves, the animations, the robotic dreary nature of it all. Sometimes it kind of just trodds along with a sense of repetition that TW2 is less guilty of. TW2 just always felt all the more mature and realistic too. The banter, the language, the mood.
I also love how decisions made in the game can have such fundamental impact on the occurrences to follow. In reality, TW2 is almost two different games dependant on which story branch you choose early on in the game. But there are many other points where there's actually more choice or freedom in how things unfold than in Skyrim, despite the differences in scale.
I'm massively enjoying both, but for me personally, TW2 had a bit more magic.