I've been wanting a crazy creek chair for awhile. I can just think of so many times that i wish i had one while sitting by fire or on the back of my truck. Also can be used as a bag.
http://www.crazycreek.com/ They usually range about $25 on up but average about $40 something.
Nalgene is another must have. I use mine everyday at school for water and keep one in my truck at most all times, they make good indestructible storage too if you get the wide mouth.
http://nalgene.com/
I bought a small AA LED maglite from lowes awhile back and use it everyday with welding, and just being a general bad ***. Everybody should have a good flashlight no matter what the situation.
3 cases of Coors/Bud light. No explaining needed.