full size spare. 
Hi lift. 
9k winch with gloves. 
tow strap. 
ratchet tie down straps. 
p/s fluid. 
oil. 
phone charger. 
cb (hard mounted)
fire extinguisher.
basic ratchet, sockets, and wrenches. 
tire plugs. 
TIRE VALVE STEMS!!! (trust me, VERY handy)
portable compressor/jump box.
1 led flashlight (stinger)
1 mag lite (the BIG one)
extra (digital, no service) cell phone with charger. 
first aid kit w/ EPI pens
at least 1 bottle of water. 
wet wipes 
most of it stuffs under the seats! 
can of ether, can of brake clean. 
hmm, there's probably more, I just can't think of it right now!!!
oh and when camping/extensive wheeling, the back seat comes out and in goes the job-box with all sorts of goodies!!!