Shirts
Pants (for dinner if nothing else)
Shorts
Sweater (the inside of the ship can run cold)
Underwear
Socks
Pajamas
Swimsuits
Cover up
Workout clothes (if you do that sort of thing on vacation)
Dress(es)/Slacks and button up (for formal night or Palos depending on your preference)
shoes (sneaks, flip flops, dress shoes)
Toothbrush
Toothpaste
Shampoo and conditioner (if you are picky)
Hairbrush
Deodorant
Razor (depending on how long your cruise is)
Sunscreen
Bug spray
Lip balm
Make up
Hair ties/barrettes
Curling/flat iron (if you need it)
Refillable Mug (I Like to bring one to fill up soda, tea, coffee....)
Light up alarm clock (interior room)
Phone
Phone charger
Camera
Camera charger/extra battaries
Portable games/charger
Walkie Talkies (We have used them on other lines with great success, but Disney has the wavephones so that may work better for you)
Watch (if you don't normally wear one, we leave our phones in the safe in Airplane mode while on our cruises)
Cruise documents (and flight info/boarding passes) in a folder or spiral notebook with everyone's passports
Magnetic white board with markers (leave on outside of door and leave messages for each other or just talk to passersby)
Post its (same idea leave messages for each other/ room steward)
Hanging shoe organizer (you can still hang it in the closet on one of the hangers instead of over the door)
Pop-up hamper/pillowcase (so much nicer than piling dirty clothes in the corner)
Duct tape (just in case)
Pirate dress up stuff (if you want, for fun)
2 bottles of wine per adult (corkage fee if you drink it in the dining room)
I think that is the usual but that may change if you have young kids, they may like a step-stool for the bathroom to brush teeth and wash hands, they may need some of their usual distractions for during dinner or in the terminal before you board....