Most badass Zelda weapon/item?

[Cornwad]

I'd agree with you on the skull hammer, but for a different reason.
Just look at Link's face when he's holding it :D

[Linkman]

Double Clawshot

That is all.

[extraz]

fierce deighty mask

silver arrows

Mirror Shield

Dual Clawshot

Ball and Chain

Magic Armour

Biggoron Sword

[Shujinco2]

One of the Medallians from ALTTP. I would say the Bombos Medallian.

Or, maybe the Harp of Ages from Oracle of Ages. That's a pretty badass weapon too!