My Minivan is pretty much my gig pack......
Some tools, LOTS of elctrical cords, splitters, extensions, power strips, Mic Cables (those orange spools hold about a dozen 20" XLR's - I carry 3-4 spools), Bag O' Mics, SM58's, 57s, 609s, beta 52, D112, Akg D5's....... Mic stands, Two Subs, 6 Powered Speakers, Speaker stands, Light stands, lights/controllers, first aid kit - duct tape, tarps, small folding table, extra inst. and speaker cables, guitar stands, a cart ......
- A bag with extra guitar strings, batteries, power adapters, cable adapters, a strap

Sometimes I bring some extra stuff too