A pharmacy. 2 Paracetamol, 2 Ibuprofen, 2 Kaolin, 2 Antiacids. To be taken before bed after a night out. Trust me.
(a stuffed toy, yes... but very cuddly indeed).
Either my George Forman grill - not for the health side of it but uni grills tend to either be built into the oven itself or useless, and it's better than just a sandwich toaster as you can do toasted sandwiches on it but also bacon for that hangover breakfast as well as cooking normal things like sausages and chicken and it takes hardly any time.
Or my box of fancy dress stuff, so useful for all my society nights out (also freshers nights out but I'm past that)