No, I'm not talking about Muhammad Ali.
Hal Jordan has often been called the greatest Green Lantern of all time. Why is that? Other Green Lanterns stand on the verge of greatness; Kilowog, Tomar Re, Katma Tui, G'nort. Well, okay, maybe not G'nort. What makes Hal Jordan stand out among the hundreds of thousands (millions?) of others who have worn the Power Ring?
Longevity? Hal Jordan has been a Green Lantern for almost 50 years real-time and 8-12 years in, what I lovingly call, comic book-time. Let's face it. Being an interplanetary space cop doesn't exactly lend itself to having a long and fruitful career. That's why the Guardians of the Universe don't have a pension plan! In the current Green Lantern & Green Lantern Corps. books there have been many Green Lanterns who have been KIA before even receiving their "badges."
Precedence? Hal Jordan was the FIRST human from Earth to have the Power Ring bestowed upon him. Humans from Earth are thought by many other alien species to be soft, squishy and too fragile to be a Green Lantern. Even the Guardians secretly monitored Hal Jordan in the beginning to make sure he was worthy, even though it was THEIR tool who singled him out as being worthy in the first place! The ring could just as easily returned to the dying Abin Sur and told him, "Nope. There isn't an Earthling on this mudball who is capable of shining your boots, much less wielding the most powerful weapon in the Universe!"
Granted, Abin Sur was dying so the ring probably picked the best choice it could find on Earth. It didn't have time to go through the entire Sector to find a replacement. So, given its limited parameters, the ring did a pretty good job.
Training? What training?? Hal Jordan was picked and immediately thrown into the fire (after taking Abin's uniform from his corpse, brrrr)! After just a few adventures, Hal Jordan found himself in the Anti-Matter Universe saving a small group of peace-loving Qwardians from execution and setting them up to live happily ever after on Earth! Whatever happened to those guys, anyway?
It was probably right after the Qwardian adventures that the Guardians DID find Hal worthy. Worthy enough to begin training him. So they sent a Korugarian named Sinestro to show Hal the ropes. It was Hal Jordan who saw Sinestro for what he really was (the Guardians obviously weren't monitoring him!) and freed Korugar from Sinestro's despotism!
So, was all of this what made Hal Jordan the greatest?
No. It was the simple fact that Hal Jordan NAMED them. He gave them their identity as Green Lanterns. It makes sense. The Guardians were just making Batteries of Power. They had no idea that what they were fashioning looked like an old Earth lantern. Especially since, at the time, Earth was beneath their notice and humans on Earth were still living in caves! It wasn't until Hal Jordan called himself Green Lantern. The Guardians thought it was a catchy title and renamed their Interplanetary Police Force the Green Lantern Corps.!
This is Hal Jordan's legacy.
Or maybe not. There have been a number of Crisis' that have rebooted the DC Universe. Has the fact that Hal Jordan named the Corps. also been rebooted? I say his legacy remains because of my reasons stated above. The Guardians of the Universe are too advanced to even know what a "lantern" is much less fashion a Battery of Power in the shape of a lantern ON PURPOSE.
Someday, when Hal Jordan has been laid to rest, whether he has died as a Green Lantern or of old age, the Guardians will erect a large shiny green statue of Hal Jordan on Oa. The Inscription will read: Hal Jordan of Earth, the Greatest Green Lantern.