"I've been looking forward to this."
"Yes, I'll bet you have."
EXIT GREEDO

Classic. A totally classic Star Wars moment, and one that defined Han Solo as a tough, take-no-prisoners, do-what-it-takes kind of guy. Just the kind of pilot you'd need to get you to Aldreaan, or away from trouble. Just the kind of action you'd expect from a man who, in just six years, became probably the most famous smuggler in the galaxy.
And then in 1997 it all changed.
Greedo shot first...
And missed!
But this isn't about that massive fan bone of contention. It's about the effect it had on the character of Han Solo.
In the original version of Star Wars (the one us fans aren't allowed to see anymore, the one that's next on GL's wanted list next to the Holiday Special and Howard the Duck) Solo takes Greedo out in cold blood. The Rodian thinks he has Solo bang to rights, just where he wants him but we, the viewer, know Han has it all in hand. And soon Greedo, who we assumed was a dangerous customer, otherwise Han wouldn't have greased him, is toast.
But the 97 version changes that.
Solo has a character arc, from callous, careless smuggler looking out for number one, right through Empire and his love for Leia to what is essentially the end of his character arc, handing the Falcon over to Lando.
It's a transition in three films from the selfish, devil-may-care smuggler to a man prepared to hand over something he loves so much for the greater good.
But having Greedo shoot first, as innocuous (and from an SPFX POV one of ILM's worst ever) as it may seem, changed that character arc irrevocably.
Think about it.