Dammit, Dagger, I'm glad I didn't read your post before I voted, because I would have gone with Vader after reading this travesty of an argument.
The Magic Cape will be extremely useful. It turns Link invisible for a bit.
Vader could easily sense things that aren't visible to the eye. This has never been a problem for him before, when he's been able to sense things through walls, or over large distances.
Then there is the Pegasus Boots which allow him to quickly get far enough away that he is out of the range of Vader's Lightsaber.
Do you really think the light saber is Vader's primary, or even his most powerful weapon?
Nayru's Love can be activated to nullify any attack for a few moments. This would be long enough for a barrage of Arrows of Light to be shot at Vader.
Try "a few seconds." And Vader could stop those light arrows in mid-air with the flick of his hand.
The Hookshot could steal Vader's Lightsaber.
And Vader could "Force" his light saber back, and steal everything Link carries in his hands.
Even if Vader did unleash powers from the Dark side of the Force.... Link has four fairies in a bottle. He would have to be killed 5 times and each time he comes back to life he'd try out a new strategy.
And what strategy would he come up with, hot shot?
If it comes down to it.... Link could deflect any type of projectile using a bottle or a bug catching net. This odd strategy worked on both Aganhim and Gannon, both of whom used powers similar to Force Lightning and other skills Vader would be capable of.
Right, because a bottle is going to stop a barrage of lightning, or the buildings Vader will force throw at Link. What projectiles are you even thinking of?
Link is always equipped for any situation and I can see him barely escaping alive with a victory here. Darth Vader would give him the fight of his life, but I am backing Link due to his arsenal of items and strategies for getting out of just about any battle situation.
Link could escape alive, but I don't think he'd come out with a victory, in retrospect.
A lesson, ladies and gentlemen, on thinking before you vote.