Heres what I lived off of in my dorm:
-Microwave Popcorn (a must for watching illegally shared movies on your computer)
-Ramen (get three boxes of Maruchan Chicken, I swear this stuff has nicotine in it or something)
-Brita Water filter (all dorms are old, all have shitty pipes, and you probably dont want to drink the water you shower in)
-Goldfish - get three boxes, the big gallon carton size.
-CheezeIts - Parmesan if at all possible
-Microwave burrito's, go for Monterray Chimichangas if availible
-Big block of your favorite cheese
-Few boxes of club crackers (green box, forget the name)
-Soda; if you drink it at all, stock up, prices on campus are rediculous usually
Also, for your ramen, look for this cool thing we have. Its a plastic 'kettle' kinda, and it basically just boils water. The cool thing is that its got a removable top, so you can pour the water out, or even just make your ramen in it. Plus, its easy to clean and is completely dorm safe (RA's get bitchy about most things that heat up)
Finally, get an Airsoft handgun and lots of ammo.