- Molgera for the music definitely. Each time I get to that part of the game in Wind Waker, I'm all pumped up. The battle is really easy tho.
- Koloktos from Skyward Sword. If there's one boss, other than Ghirahim, that was great to fight, it's definitely Koloktos. One of the greatest designs I've seen in recent TLoZ titles. Really fun.
- In Twilight Princess, any boss could be a favorite, design wise. Probably the game, imo, with the coolest looking bosses. It's a tie between Blizzeta (for the music) and Stallord.
- Byrne in Spirit Tracks is really fun to battle and is overall a really interesting character.
- Gleeok in Phantom Hourglass is also fun to fight. Reminds me a lot of Twinrova in OoT.
- From OoT, it's between Twinrova and Volvagia. Great battles and great boss concepts definitely.
Haven't played the other games unfortunately.............................................................. I should probably do something about it. Majora's Mask is next that's for sure.