I thought Eox was the most fun. The fact that he took up two whole screens was kind of cool and the way you fought him was nice and creative. Although the music wasn't that good I still thought it was kind of fun to play. When going through the temple he's in (It's been awhile since I've played so I forgot.) I always get so excite. Ifeel like my heart might explode because I get so excited.
Either Gleeok or Eox because they were the most hectic of the boss battles in this easily bad game. I love the boss music which spiced up the battles.
The jumping to attack Eox thing was the funnest thing in his battle though; I just loved being able to jump and smack him multiple times, it was like a punching bag. :3