I used these items in the graduate housing at Stanford, but they would also work for undergraduate housing. I found the feather bed topper to be a MUST and the bed risers really gave me some much-appreciated extra space!

Feather Bed Topper ($60)
(Similar to this: http://www.bedbathandbeyond.com/product.asp?SKU=104060)
XL Twin
White
COMFORTABLE!
Made all the difference on my dorm bed!!

Dorm Bed Risers ($10)
White
Provides extra room under your bed!

Sheets ($10)
Includes Fitted sheet, Flat Sheet, Two Pillowcases
XL Twin
Jersey Knit
Beige