Well, I guess that all depends on how rough you want to go. And if you want my opinion, the less you take, the more you'll enjoy your trip.
Whenever I go out on these things and I'm packing, before I put something in the car I ask myself, "Can I survive without this?" If the answer is yes, I leave it. This usually means I go out pretty sparse. Usually I only take the clothes on my back and a few pieces of warm gear (coat, hat, gloves) just in case. Then comes my tent, sleeping bag, and pillow. And other than that, that's about it.
But, and here's the part you asked about, there are always a handfull of items I make sure to take that I absolutely cannot do without. I strongly recommend taking all of these with you on your trip.
1) A Q-Beam. This is an incredibly high powered flashlight used by hunters and fishermen. They can usually be found at an Academy for as little as $10, and believe me, they're worth every penny. The woods get dark at night. These things will light up an entire area like it's noon. Hunters use them for deer and rabbit spotting, fishermen use them to attract fish at night. You don't need to be either to enjoy this, though. And it plugs into the cigarette lighter for power.
2) A handheld GPS. This is going to be more expensive than the Q-Beam, but if you're going somewhere remote it will also be worth every penny. Nothing is worse than getting lost on an unmarked road in north Texas. This small device may literally save your life. Go ahead and shell out the $100 for it. Again, worth every penny.
3) Dinner. This includes firewood, lighter fluid, newspaper, and lighter. Also, a pot, some water, and a big can of stew (grocery store). When you're hungry build the fire, open the can of stew, and set it directly in the fire. That is good eating. In the morning stoke the embers and make yourself some hot tea. Man, there is nothing better than waking up in the dew and boiling you own hot tea on a fire you build.
You guys have fun.
