You have no idea how hard it was to pick one. I ultimately chose Ganondorf, but here's why. Zant was an absolutely terrifying, imposing villain throughout Twilight Princess. When I played it (can you believe that it was made 7 years ago!?) his theme gave me nightmares. He was so scary. He was menacing. He was just outright creepy. I loved him for this. It truly felt like a villain that I wanted to destroy, especially after the Water Temple, when he outright WRECKS Midna. Had they chosen to focus on this the entire time throughout the game, instead of making him a stupid monkey man, he would have been chosen. Ghirahim was absolutely amazing. It was a tough choice between him and Ganondorf. I feel that Ghirahim was what they were ultimately trying to do with Zant, and this time they did it successfully. I really loved him as a villain, because he was just so funny, and yet so evil. He knew exactly the buttons to push every time.
This is actually true. I am the Ghirahim of HC. I always know exactly which buttons to push. I am also hilarious and evil. :D