RE: You have to choose ONE gun...
I keep my guns in either a fire proof gun safe, or an aluminum gun case for just this reason, so they'll either survive the fire, or I can grab the Aluminum and take out 6 with me. If I could only take one, I'd take either my Ruger markII m77.30-06, my baby, or my most recent buy for my girlfriend, an 1894 German made Mexican mauser, it's 108 years old, so I couldn't let her burn.