1999 - Sean Elliott's Memorial Day Miracle
Honestly, the 1999 playoff San Antonio Spurs were so dominant that they would've won the title even without a number of clutch shots they hit that postseason. Still, while Avery Johnson's title-clinching NBA Finals shot was huge in the grand scheme, nothing in that playoff run can touch Sean Elliott's Memorial Day Miracle.
The difficulty of the shot is easily a 10, as he had to tightrope the sidelines while turning, get on his toes, and then shoot over the outstretched hands of Rasheed Wallace. He did all this with the Spurs down by two and nine seconds left in the game.
Elliott's heroics allowed the Spurs to take a 2-0 series lead instead of heading to Portland with the series tied 1-1. The Trail Blazers never recovered from the moment, losing the next game by 22 at home before falling 94-80 in Game 4 to lose in a sweep.
In 2020, I did a deep dive into this shot in determining the single biggest shot in Spurs history. The article also includes a shot you'll see later in this list.
This shot is certainly the most memorable one in San Antonio Spurs history, and I'm not sure that's ever going to change.