The Omega Speedmaster took the number one slot on Robb Report’s list of the 50 greatest watches of all time. That may seem odd for a monochromatic steel chronograph. Still, because the Speedmaster was the first watch to go to the Moon, it is the pinnacle emblem for the mid-century derring-do that so many collectors look for when choosing a vintage mechanical sports watch. Perhaps more importantly, the Speedmaster has become forever associated with NASA.

The Speedmaster wasn’t designed for pilots. Instead, as its name suggests, it was built for speeding along here on Earth in a car. It was the first chronograph to place its tachymeter scale on an outer bezel rather than on the edge of the dial inside the crystal. This improved driver legibility while creating the iconic look of technical chronograph tool watches that persist to this day (consider the Rolex Daytona, as well as various iterations of the Zenith El Primero and the Heuer Autavia).

When the Speedmaster went to the Moon on July 21st, 1969, a line in horological history was drawn. We now have what most call “pre-moon Speedmasters,” more broadly called “Moonwatches.” And while that demarcation is clear enough, the realm of Speedmasters is otherwise vast and hazy. As James Lamdin of Analog Shift tells Robb Report, “If there were a four-year college degree in vintage watches, an entire semester would be dedicated to the Speedmaster alone.”

To cut through the fog, we reached out to five experts and asked them, “What are the coolest, most tasty vintage Speedmasters to collect right now?” We wanted their passion to come through along with their expertise, and their answers reflect both.