that's a pretty wide question.
I think alot of it depends on who "you" are (Age, sex, # of people with you, their ages and sex) and what time of year you are going.
Geneally, anything you take with you on a dya outing (THink, Zoo, amusement park, even Mall if you tend to be an "All day" shopper) would give you an idea of what you "need" at WDW.
ALthough I have to say I take far less with me to the local zoo than to Disney. Well actully that's not true either since I do not take a diaper bag into the WDW parks.
THere are plenty of "What to pack" lists out there.
If you give us some more information, we may be able to better answer you.
Hi~
Thank you for answering my question with another question, I really didn't think that one through did I? LOL I'm a mom

36 yrs. and traveling to WDW for the first time with a teenage boy 14 and a young princess

7, they are both excited to be going to say the least, although I think I'm the one most excited, DH seems to care less.

. I'm doing all the planning and want to make sure I'm doing it right, here's my list of things to get.
Panchos,Autograph books,Big pens,Sunscreen travel size and normal,back pack for self-not to big,Digital camera,glow-sticks to buy ahead of time,snacks,water bottles,mini-fans for the kids,video games for long lines,sunhats,sunglasses for everyone, lots of zip locs.
OK that's what I have so far to take to the parks, oh and everyone has to wear a fanny or back pack. I'm not carrying anyone stuff!
We are going to be there May 23rd, through the 30th, staying at PC. Not sure what the weather is going to be like other than muggy and hot. I'm doing the
DDP, I've made all the ADR's, really happy about my choices

(read lots of reviews), I've made out most of what we need to hit while in parks (when they open and then later at EH's). Hmmm not sure what else, Oh did I hear somone mention a barber shop to get a special hair-do for cheap in the MK????
Thank you everyone for your amazing cherished advice. God Bless you!