The Hookshot is a recurring item in the Zelda series. While it appeared a few times in the 2D games, it was the 3D ones that made the lasting impression on me.
Mainly because it gave you such much depth. You felt rather proud lining up the laser-beam and reaching a high-area for the first time. Which also led to a lot of secrets to be found by using it.
It could also be used in battle. It's not nearly as awesome as a bow and arrow, but it has it's uses. Unless the foe is immune to it, as they often are...
I also love using it in the Super Smash Bros. series. It's such a great grapple weapon, and it's personally saved me from many falls in a match since it can attach to a cliff's corner.