[Hitman]

Depends on a lot of factors. You'll find that most people have a couple of gear sets for different hills.

How long is the hill? What grade? What altitude is the event at? What rpm do you want to be at, at the top of the hill? What gear do you want to be in at the top of the hill? Will you drive the car home after the event with the hillclimb gear set?

Lots of details.