ALL OF THEM.
Just kidding ha ha I would say... The deku leaf. Just think of the possibilities! Jumping off buildings are soaring around town! Then landing in the street and getting hit by a car. I change my mind... The Pegasus boots, then I could run around in fields, I would kick everyone's butt in tag, and then I would run into a tree. I change my mind again... Maybe golden gauntlets like mastersword said, that would be wicked until I accidentally murder someone by throwing a car at them... Blah, I'm over thinking it ha ha xD