small coffee pot,paper towl holder (rubermaid one does great easy to change rolls) extra extension cords,we keep ours pluged up all the time except winter to keep refrig going so we dont have to empty all of the drinks etc when we get home we just restock it. we use a adapter that goes into a regular 110 plug just for that reason not to run air or anything,it also helps keep batteries charged up. good luck with your trailer and happy trails..

Just about every thing I own!!.  You never know what you will need.

I stocked mine with plastic ware, styrofoam cups (hot and cold drinks) cheap knife set (in case you lose one). Paper plates with the camper wicker holders for support. a set of metal real plates and bowls. Have the metal cups that husband won't use. A set of real silverware (cheap also) for steak and such. A medium pot, fry pan with lids. A griddle. 2 long lighters. A thin coleman camper stove for outside. A cutting board. A $20 propane grill that stores under the seat. A large metal coffee pot that I heat water in. I measured my cabinets and found some plastic storage containers that I store the silver/plastic ware in and label.  I have another for the potholders and dish towels. Extra paper towels, napkins, toilet paper.  I keep a large rubber band on my towel holder to wrap around the towels when traveling.

I have a small bottle of dish detergent and liquid hand soap.  I left mine in over the winter one year and they were too full and expanded out the top. Messy.  Canned goods. I have a sealtight container I put instant potatoes, instant oatmeal, hot chocolate, etc. in also.  I leave the plates in the plastic wrap and take from the bottom. The styrofoam the same way.  That way they are protected where you eat.  I bought new towels and took the old ones to the camper.  A fan and electric heater when you don't need to fire the furnace up (and have electric).  And of course those little samples of toiletries.  And everything I found at Walmart.

Extra set of clothes & boots, jacket, gloves, rain gear & boot slickers (can you tell I've been caught out in the rain?), hand and feet warmers you can put in your socks or gloves, medical supplies for horses & people, flashlight, bug repellent, fire starting supplies like matches or lighters, duraflame firestart, indian fire water (charcoal fluid)  & anything you'd use to cook over fire like hotdog sticks etc., 

Anything I think may not fair well in cold weather I put in boxes and store in our semi-heated garage.  

I keep everything in the LQ through the winter, trailer plugged in, and run a ceramic heater all winter set to about 55 degrees.  Don't have to winterize the plumbing and it keeps it from smelling musty.  

So I recommend a ceramic heater for when its being stored in the winter. 

I keep one of those six pack wine holders you get at the grocery store to keep wine bottles safe while traveling.  And I keep plastic wine glasses for happy hour.  I think someone mentioned that already. 

I also vote for disposable everything, when possible. 

Gee I never thought of keep my LQ heated all winter. When its 20 below I am more concerned about keeping my house warm.

I used to have to pack the trailer prior to an event- hauling stuff out of the house only to haul back in again so i went and bought another hair dryer,hot rollers, curling iron  as well as toaster,iron and of course bathroom items ( make- up,lotions,toothpaste and brushes) . That way its ready to go and I don't have to lug it around. For the most pasrt, its used up before winter and I don't have to unpack everything.

http://www.horsetrailerworld.com/forum/thread-view.asp?threadid=5626

here's a link to a thread on this last summer with some good ideas,too

I'd add pop-up hamper for dirty clothes, lantern, door mats for outside LQ doors, plastic trash or store bags for yucky stuff.   I really like my fabric 6-shelf hanger, $12 from Walmart, holds lots of stuff, hangs on the clothes rod behind the toilet. Also over the door 12 pocket organizer hangs on door to horse area with cleaning, toiletrie and first aid stuff.  Also wire shelves and dividers  make cabinets way more useful.  I use baskets for storing like things together. That way I can take all of it out of cabinet and put it back with one motion. 

Take more water than you think you'll need and don't forget the chocolate!  Happy Trails.