Silverless Ganon
Defeating Ganon without possessing the Silver Arrows. Normally, in the fourth and final phase of the Ganon fight, the player is intended to stun Ganon with the sword and then shoot him with silver arrows to damage him. However, there is a small window right when he is beginning to teleport where Ganon is vulnerable to being damaged with a sword spin. Hitting Ganon too early will stun him, which does no damage, and waiting too long will miss.
It takes 12 successful spins with the Tempered or Butter Sword to kill Ganon this way, and 24 spins with the Master Sword. In comparison, it takes only 4 shots with Silver Arrows to kill him.
Another popular glitch to use during a Silverless Ganon fight is the Torch Glitch. This allows the player to only have to light one torch instead of two to make Ganon vulnerable.
Thanks to Avonyel for suggesting this entry and providing content, and karl for suggesting a link to Torch Glitch.