If you haven't already, I would suggest picking up at a minimum the trooper skid plates for a little under belly protection.
Basic recovery gear...tow straps, shackles
A pair of gloves
small shovel
a good general mechanics tool set (wrenches, sockets, screw drivers, various pliers, allen wrenches
water, oil, diff fluid, tranny fluid
as above...if mud or water crossings...an alternator
manual hubs are a good idea
propper tires...a good all terrain or mud terrain

the list could go on and on
a lot will depend on the terrain type and driving style