I am always a fan of giving out useless items to my players. And then seeing what they can do with them.

Like a Hair Band of Glorious Hair. Your hair looks fantastic, and blows in an invisible wind. Bonuses only to hair based situations.

A ring of land walking. Lets you walk on land at your current land speed.

A staff that once a command word is spoken stands perfectly upright and still for an hour.
A little disappointed with myself for not seeing that being used as a stripper pole right away.

And a ring of lava breathing. Lets you breath lava, but doesn't protect you from the fire damage.