The five most important things absent family and pets are:
Wallet
Personal Records
Laptop
External Hard Drives
Photo Albums
If I had to get rid of three of those, I guess it would have to be the laptop, photo albums, and records, since most of the important data from the laptop would be stored on the hard drives, and most of the photos and records are copied in digital form on the hard drives as well.
But that's a tough call to reduce it down to two things. I keep the external hard drives, photo albums, and the personal records file in a locked emergency box with handles on it to grab and go in case of a fire or other emergency, and my wallet and laptop are always near me, so in reality unless the fire was rapidly spreading and completely overwhelming I'd probably be able to get it all after making sure everyone was outside and grabbing my cats.
I should probably just get a fireproof safe and not have to make the choice.