The other day, we smelled gas in our home* (natural gas -- this is not a comment on my lack of cooking skills). I called the gas company and they told us to leave immediately and wait for the gas guy to come and check it out. I told everyone to grab what they needed and to go outside. It was quite eye-opening to see what my family considered "essential."
Me (Lois) -- purse and car keys (give me a credit card and I'm fine; in fact, I was secretly hoping that the place would blow up so that I didn't have to clean it anymore).
Nigel -- photocopies of all of his artwork and some sketch books (gee, is anyone surprised at that one?).
Frances -- our pet rabbit, her favorite teddy bear, her favorite bandana, a poster of Zac Efron (I kid you not) and a "ecstacy/rave" binky (she says because it has a whistle and light). She later lamented that she forgot to bring a book (luckily I always keep one in the car -- never know when "Cujo" is going to trap you in there for days).
Jeffrey -- his favorite (and largest) Lego set, his 1st Grade math trophy and a can of red spray-paint (what?).
Alice-Grace -- a tiara, a pearl necklace and her favorite stuffed animals (keep in mind that she forgot shoes).
I'm sure that I forgot some of the items, but you get the gist of it.
Of course, our 72-hour emergency kits were in a state of disarray (I started reorganizing them months ago and never put them back together again), so we couldn't bring those.
*Luckily, it was no big deal -- just some problems with our water heater that were easily solved.