Duct Tape (fixed everything from a split radiator hose to a blown out ugg boot)
Cable Ties (fixing stuff, hanging stuff, holding stuff, tying stuff)
A bucket (cleaned with it, filled water in it, peed in it, spewed in it) not all in the same bucket
Leatherman multi tool (cause it makes me look like i know what im doing when i have no idea)
Beer (you can celebreate with it comiserate with it, have one when you have stuffed up which makes you stop and think and can ofted stop a bad situation becoming worse)