As far as impressive feats in sports go, throwing a no-hitter is unique. For a pitcher, throwing one is rare and difficult to achieve, but unlike other baseball accomplishments—say, winning the home run derby, or hitting safely in 56 consecutive games—it is not an individual effort. The feat requires teammates to support the pitcher every step of the way (and the umpire to make the correct calls).
And unlike other special achievements in baseball, no-hitters are kind of...democratic. Sure, a number of Hall of Famers have accomplished the feat. But so have journeyman pitchers, guys with great comeback stories like Carlos Rodón and those who had thoroughly underwhelming major league careers.