If you didn't cry at the end of the game Metal Gear Sold 3 then consider your man card revoked.
Compass: Depending where you are for your polar expedition - the Poles could make for a trippy compass reading - this is a must. There are not many road signs to guide you along the way.
Flashlights: These LED bad boys are small, bright and last forever. Pack a few and bring some extra batteries, too.