Toiletries for yourself, going home outfits for baby and you (I personally wear the hospital attire while there cause its always a messy first couple days, especially if you are a FTM) pads and underwear for sure. Depending on where you live the hospital will provide most everything else - diapers, bum cream, Vaseline, washcloths, blankets.
PHONE CHARGER! & snacks!!! clothes, for you & Lil one to go home in, & for a few days in case you have an extended stay. (My first stayed in the nursery for 7 days) Pads & underwear... are top things. The hospital I delivered my first in provided everything else.