What things are you good at?
What's the ability that you're most proud of?
The only restiction is that you've had to practice/invest yourself to get good at it.
Examples: Dancing, writing (novels, poems, etc), singing, marathon running, weight-lifting, fencing, playing an instrument, speed-typing, high-skill video gaming, origami folding from memory, martial arts, target-shooting, high-skill cooking, skate-/snowboarding, rock climbing, billards, ping pong, darts.