Keep Master Sword During Ganon Fight

During the fight against Gannon, it is possible to keep your sword. By far the most common method is using a Superslide into the cutscene.

Superslide

Superslide into the cs trigger, and hold up your shield until Ganon "hits" your sword away and Navi starts talking to you.

Spell

Right before you hit the cutscene trigger hit a button for a spell (I know it works with Din's fire) and after the cutscene, you should still have your sword.