I haven't much time to post, so let's get started with one category:

Swords: Well, let's see... since there's plenty of customisability in this category, I feel that 7 wouldn't be overdoing it too much.
* Deku Stick (power 1, beam power 3, beam hearts 255): This sword can only fire beams when you have the Peril Beam Scroll. Yes, I know it's cheesy to make the Deku Stick have a "hidden power" that is only activated under secret conditions, but I'm throwing this idea out here anyways.
* Wooden Sword (power 1, beam power 1, beam hearts 100%): Sold in Hyle Town for a bunch o' Rupees. Like the Deku Stick, it can be eaten!
* Iron Sword (power 2): Sold by weird Subrosian swordsmiths in secret overworld caves, in exchange for your Deku Shield or something. As it is made of cold iron, it is incredibly un-magical.
* Light Sword (power 1, beam power 1, beam hearts 0%): Sold by weird Wizzrobe... swordsmiths?
* White Sword (power 3, beam power 3, beam hearts 100%): It is one of the treasures of Hyrule's royal family. Pity that Link had to lose it, though.
* Four Sword (power 4, beam power 4, beam hearts 100%): The source of Sarai's greatest power. Only in certain rooms does this completely optional sword's power enter the picture.
* Golden Sword (power 5): Only available during the final battle.