I loved the forest temple, in fact it's probably my favorite OoT dungeon, but Phantom Ganon is the subject of my unconditional ire. I ran out of arrows, and died enough times that the pots in the entire temple were empty when I re-spawned (except the one in the back with the fairy, for some reason...). I was a bit younger at the time, and my memory is hazy, but for some reason I refused to leave and go buy arrows and come back, I can't remember why.
So instead, I stood in the corner hoping that the painting he's come out of was one of the two close enough for me to hit with the hookshot.
Yeah. I was that stupid. I eventually beat him, though. With the hookshot. I don't know, maybe I got more arrows, I really can't remember. But I do remember hating every second of that fight.
As far as FAVORITES go, Dark Link. Far and away. Even though he's a Miniboss. As far as REAL BOSSES:
Even though Dark Link is TECHNICALLY a miniboss, I liked that battle, as well as Barinade. The final battle was ABSOLUTELY AMAZING! It actually took me a few tries because I ran out of magic and I didn't realize I could lure Ganon to knock the pillars down. But I beat him and the satisfaction I got was the best!
This. word for word. LolGames4U, you rock.