I actually loved the last fight Ganon. He was pretty hard and love the cutscenes where you stab him. But 2nd place would be... Bongo Bongo. Twin Rova was fun, because of the cutscene but it wasn't challenging enough in my opinion. Far to easy!
In this fight, you couldn't stand around for more than a second without getting zapped. Seriosuly, what an active battle. You had to be running around the whole time. Those lightning beams were awesome shooting all over the place.
Phantom Shadow Beast: Bongo Bongo.
I love that name XD
He was my favorite boss throughout the game, probably one of the most difficult bosses in that game aside from Ganondorf. I loved the battle. The battlefield being a drum is what made it unique. He was the only boss to almost make me use a fairy because he knocked me off the drum.
If I'm happy my favorite boss is Twinrova. Those two hags were evil and had the look of the classic witch look, but they have that look to show off their mighty magic of Ice and Fire. And when those two combined, that's where the fun begins, reflecting their own powers makes me happy to beat them! And I got to see a funny scene at the end of their fight.
If I'm mad, Ganon is my favorite. I vent my anger on that beast form of his, to end his reign and to beat the crud out of him. He's evil. That's ALL the reason I need to beat him and vent my anger upon.
If I'm playful, cheery, careful and sarcastic, then Morpha appears. I like to play with that gelatinous beast. It's fun to lure it into a corner and slash like a madman. It makes the boss battle end quickly and more rewarding. Though I get carried away and let my guard down, this is also where I got a few "game overs" in OoT.
If I'm scared, Bongo Bongo. That boss creeped the **** right out of me. He's big, has disembodied hands, can make an ominous beat while beat you while he is invisible. Though beating him without using the Lens of Truth is more challenging, and terrifying, I prefer to do it. I never know what will happen, nor will I know when he will strike me.