One in a deep forest...
I like the Forest Temple - it actually feels like a temple, in a way that most of the others don't. Finding my way around has never really been a problem (impossible geometry besides), none of the monsters are particularly nasty, and most importantly Link gets a bow. I've mentioned this before, but I always envision Link as an archer, and having a decent ranged weapon solves an awful lot of problems.
The core of the temple revolves around finding the four Poe Sisters and recovering the flames that they've taken to raise the lift to the basement. Two of them hide in paintings, the third hides in a sliding block puzzle of all things, and the fourth... it's actually rather sad, as once you've defeated the first three you find her back in the central room, weeping for her sisters. They're also individually named - Joelle, Beth, Amy, and Meg - unlike nearly every other non-boss enemy in the game.
I now feel a bit mean for attacking them. They're more than the usual mindless monster summoned by Ganondorf. Then again, they did start things by running off with the flames for the torches in the main room...
Poe Sisters aside, the rest of the temple has a good mix of enemies and the traditional sliding block puzzles to contend with, along with a few more unfriendly foes. The Stalfos are quite fun to fight as if you Z-target one then the other will back off and circle you, though potentially also rather frustrating as they respawn if you don't kill them quickly enough! They also have shields and actually know how to use them. Oh, and just to make things even more annoying there's a room with a hole in the middle where you fight some of them - they can walk across the gap without falling, unlike Link (oops)! That was a pain as I had to backtrack a fair bit to get back to there.
The impossibly twisted corridors I always found a neat trick, and a bit of foreshadowing of other impossible geometry elsewhere in the game (the infinite room in the Water Temple comes to mind...). They're also where I first discover the Wallmasters, which have had a slight upgrade for OoT 3D - they're scary enough with the ominously growing circular shadow and descending noise, but now they get a hand-shaped shadow. Nobody likes the Wallmasters.
Another change for 3D: the corridor leading to the final boss now has paintings on the walls. I do like that OoT 3D is not merely a direct port, but that they've taken the opportunity to add more detail in places. Unlike, say, Myst for the 3DS which isn't even in 3D!
Ganondorf - or rather, Phantom Ganondorf - was pretty much exactly as I remembered, complete with the trick of being able to tell which one is real and which is fake by the real and fake ones riding to different sides of the paths in the paintings. And the final playing-
Finally, there's by far the most hilarious part of the whole Forest Temple, and that's the long drawn-out scream Link lets out right at the end when the Deku Tree Sprout pops up and knocks him over. Seriously, you've just fought your way through the first real dungeon, dealt with Wallmasters of all things... and now you're scared of a tree?
I will always be... your friend...
Saria, Sage of the Forest Temple