and make them early.
The closer the trip gets, the more likely you are to get in that last minute panic mode and forget something important that you had thought of previously. I am forever getting that "it seems like we're forgetting something" feeling when I don't write things down when I think of them. Usually, I don't get too far down the road and I also get that "aha, I know what it was now we were forgetting." And sometimes, we just have get it when we get there (as long as it wasn't a child or something).
Here are a few additional items I have on my list that we always need.
reservation info, driving directions (if a first trip to a new resort), AAA card, insurance info, updated immunization info (if travelling with a pet and you might need to board them), travel size woolite (great for rinsing things out in the sink in an emergency), cameras, extra film and batteries, eye glasses and
, contact lenses and cleaner, prescriptions, OTC drugs (tylenol, advil, etc.), deodorizing spray (for those musty rooms) and disinfectant spray (bottoms of showers and tubs), water shoes (for pool and water rides), chargers/power cords for electronics (that cell phone battery only lasts so long), and a couple of garbage bags (in case you have some wet clothes or bathing suits to deal with or pack).
We will also have at least a personal first aid kit or two for putting in fanny packs so you can grab a quick bandage if needed. If you will be doing a lot of walking, you may want to customize it and add some moleskin for blisters.
Depending on where you are staying, the time of year, and how long, you may want to bring some additional items, such as:
Suntan lotion, insect repellant, laundry detergent and dryer sheets (I usually put what we need in ziploc bags), a bottle of liquid hand soap (easier than those small bars you often get), extra coffee and filters plus any special items you like such as splenda or that favorite flavor of creamer.
If the drive is long, most everyone grabs a pillow, which makes it easier to sleep during the trip, and maybe a throw or two for those who are cold natured.
Hope some of these help. BTW, my list has gotten much longer with some of the great suggestions I have read on here already too.