I think in my case, it would be: "Man suffocates in house fire while trying to figure out which beloved poker chip set to save".
I have several heavy favorites, and a few that simply could not ever be replaced. Even deciding now -- under no time/death pressure -- is nearly impossible.
Probably one of these four: Four Queens, 20th Century, GCOP, or the recently-completed x18 tourney set (Regency, Copa, Eddie's, Casablanca, Circus Circus). But many others that are just as nice or nicer: several Star sets, 43mm tourney set, mixed-casino cash set, Riversides, Jessie Becks, Money Trees, etc., etc.
But one thing is for sure -- my first priority would be the wife and four puppies.