Han Solo shot first.
What I mean is, he's the one who started the series of events that led to the destruction of the first Death Star. It began, actually, despite popular belief, with his theft of the technical plans for the superweapon. You might have heard differently.
The truth is, that's why he was being pursued by the Imperial fleet when he dumped his cargo load, the smuggled goods that were meant to continue his cover as an operative of Jabba the Hutt, the job that landed him in such hot water, that led to the bounty on his head, his encasement in carbon freeze at Cloud City by Boba Fett, and eventual rescue by the same allies he'd been assigned from the start, Princess Leia and Luke Skywalker.
I know the stories you've heard. It was Leia who stole the plans, downloaded them into a droid and jettisoned it in orbit of the desert world Tatooine. Han himself randomly enters the picture when Skywalker comes into possession of the droid, which insists on the meeting with Obi-Wan Kenobi and the need for a ride to rescue Leia, who just so happens to be a prisoner aboard the Death Star.
Really. Stop and think about that for a moment.
The truth is, none of what resulted would have happened if Han hadn't been an agent of the Rebellion all along. Random chance doesn't put together such crucial alliances like that.
Han's ship, the heavily modified Millennium Falcon, was a ship he'd won from a bet with Cloud City administrator Lando Calrissian, a man who at the time of Han's capture there was in known collusion with the Empire, and who had also authorized Fett to operate in the open. Don't these coincidences strike you as a little forced? Why do I have to explain any of this to you?
The real sequence of events:
Han steals the technical schematics. He brings them with him to Tatooine, where he knows an old hermit living there is really one of the last Jedi, Kenobi. He also knows, as does the whole Rebellion, that Darth Vader is really Anakin Skywalker, the father of young Luke, who at this point is being raised by his uncle Owen. He implants the plans into a droid, ensures Uncle Owen purchases the droid, and as Skywalker is cleaning the droid for service he stumbles into the recording of Leia asking for the assistance of Kenobi. Skywalker is intrigued. He seeks out Kenobi, heads to Mos Eisley spaceport, and runs into the only available pilot, Han himself, willing to take the job of transporting them to Alderaan.
Except, Han knows they'll never reach there. He knows all about the Death Star. He's headed there now because it's the one place the bounty hunters Jabba contracted against him won't go. With Vader focused on his old enemy Kenobi and his son Luke, he'll prevent Han's dangerous position from being exposed, make sure everyone is focused on the wrong targets. To the Imperial forces, Han is no longer the man who stole the crucial schematics but rather just another ally of the men who must be eliminated at all cost.
After rescuing Leia, they manage to escape, because someone, namely the clever Governor Tarkin, is smart enough to realize what's really going on, a tracking device safely hidden aboard the Falcon. Maybe Han knows this. Maybe he's planned this all along to force the crisis that will draw the Death Star into direct conflict with the Rebels.
He stays away from the actual assault, of course. To Skywalker and Leia, he's exactly the random ally history remembers him as, certainly no one who would be looking to actively fight on the side of the Rebellion. Except he returns at exactly the right moment, when Skywalker needs that last little bit of assistance to deliver the volley that destroys the Death Star.
Han begins to work openly with the Rebels. The bounty hunters are still after him. The Empire, which usually has nothing to do with such scum, begins working directly with them, and the convergence at Cloud City occurs. Except this is another con job, Calrissian another plant. Who better to ensure Han's safety, make the recommendation for carbon freeze rather than anything else Fett might have had in mind?
Later, in the operation that destroys the second Death Star and ends the Empire, both Han and Calrissian are actively working as top level soldiers of the Rebellion.
None of this ever caused you to wonder? Well, now you know. The only man capable of sabotaging his efforts, Tarkin, is lost in the destruction of the first Death Star, and Vader is sidetracked immediately by his obsession with Skywalker, a necessary conflict that allows the destruction of the second Death Star to end the Empire. It all makes sense, doesn't it?
So, Han shot first.