Twilight Princess's dungeon design is top notch, but the overworld of Wind Waker is something special. Honestly, I don't really know which one I prefer, which only makes me want these ports to come even sooner. I used to prefer Twilight Princess by a decent margin, but I honestly don't know anymore. I could easily see Wind Waker overtaking it.
Same thing happened earlier this year. I've always preferred Ocarina of Time, but when I replayed both of the 3D remasters I found myself liking Majora's Mask much more overall.