laptop or netbook
wallet (to hold rail card / debit card /student id / loyalty card etc!)
phone / smartphone
a printer (can come in useful for printing off past papers / lecture slides, esp if you live far away from the library or uni!)
a music player (useful for long journeys / spare time)
a diary or wall planner (comes in handy planning your time / counting down the days until uni's out)
several extension cables (esp if you have lots of appliances)
a lamp
electrical appliances (kettle/ toaster etc)
pen & paper (plenty off it - this is the only thing you really need)