There really only is one or two.
I started with nice watches, then had to sell off anything decent to life problems. My first watch "back" was an Omega Seamaster Pro Chrono. Wore it every day for years, it doesn't get much wrist time now, but it's a forever keeper.
If hard times hit me again, I'd imagine I would sell everything but the Omega, but the last to go would be the Rolex daytona. Not because it's my favorite, that would either be a Panerai 162, or an AP Royal Oak Offshore, but because it's one watch that I feel would have value for the people who get it once I'm gone.