Chewable multi-Vs, remember gummies don't contain iron. If you sons are picky eaters (like my daughter) get the hard kind so they get enough iron. BUT I also keep gummies so she can double up and not get iron poisoning.
Halls defense in strawberry for a mega dose of vitamin C, which did a good job on her last cold.
Mucenex powders in orange cream.
Children's Advil liquid or Tylenol chewables for fevers and headaches. The listed doses on the bottle are low, I got a more accurate chart from the ER.
Little noses saline rinse or an irrigation syringe and warm water with salt to flush out the snot. The best way to deal with a stuffy nose is to flush it out, but kids don't like it...so some holding down, kicking and screaming may be involved. But it works!
Kid's pepto chewables for sick tummies.
Gatoraid powder, lasts longer than premade juice. Hydration is key!!
Reuseable jel cold packs in the fridge, for headaches or to bring down a high fever fast when packed under the armpits.
A really nice (and quiet) humidifier with built in nightlight.
Lots of extra sheets, blankets, pilowcases, and towels for those night time quick vomit clean up. Plus, plastic pillow case liner to keep the pillow from smelling like puke.
And of course, chicken noddle soup and saltine crackers to settle queezy tummies.
Edit: On thermometers, get a good one that uses button batteries and keep spares (watch batteries last forever). or the old fashioned ones with no batteries. BUT don't mix up the rectal one (for the little one) with the oral one (for the big guys).