-sewer hose extensions (some sites suck with utilities placements)(and good ones like Rhino
-clear 4" elbow so you can see when you've flushed the tanks enough(running clear)
-30 amp ext. cord, same reasons as above
-extra propane regulator (sucks when they fail in the bush)
-various hose clamps, fittings etc.
-roof patch materials like Eternabond tape, and self leveling roofing caulking and gun
-aluminum foil tape, good for emergency patch jobs on the trailer, like a hole in the fiberglass sides etc.
-can of spray foam for underside hole filling(mouse prevention)
-basic tools (usually on my truck anyway)
-welding machine to repair trailer frames (have done this in the bush)(not something I carry though)
-lots of blocks (2x6's)for leveling as some site really suck for being reasonably level
-hatchet, axe, wiener sticks, pie irons
-wheel chocks like X-chock for securing trailer and reduce rockin and rolling
-Tire pressure monitoring system for trailer tires
-side rails on exterior of trailer for hanging BBQ, shelves etc.
-aux. propane hook up by BBQ location
-aux. power connection at front of trailer for plugging in generator in the back of the truck without having to get out a mile of cord
-PROPER QUALITY TIRES!!! not china bombs!
-led light at the back of the trailer for night time parking
-lights in all storage compartments for night time searching and long dark storage compartments
-led lights on the sides of the vanity mirror for the wifey
-extra shelving inside cupboards for better storage
-jack stabizers to help trailer rocking (three teenagers move allot!)
There's more!