North Pole is probably the easiest line you can access from the North Pole Gate
. The entrance -- while usually fairly rocky -- isn't too steep, and it's wide enough that you've got room to maneuver a bit.
Once you get in, you've got plenty of room to choose your turns, and you can head a fair distance both left and right to mix things up a bit. Once you've made it past the often rocky top section, there's nothing left to do but enjoy ~500ft of sustained 30+ degree turns.