Well, it’s a bit all over the place, I let my imagination run wild coming up with it.
The main diversion from the canon Star Wars timeline is the survival of Mace Windu (I know, totally original). After Order 66 is executed and the Empire rises over the galaxy, he goes off the grid. During his exile, he meets a couple of tech-savvy mercenaries who agree to help him hide from the Empire, as well as bounty hunters. After a while, Mace is quite sick of exile, and of the Empire forcing him into exile, so with the help of said mercenaries, he airs a message at large across the galaxy, encouraging people to rise up against the Empire. The message would end up working, as some in the Middle and Outer Rims would rise up and topple the local Imperial governments, separated into two factions: the Alliance to Restore the Republic, and another faction that also wants to restore the Republic, but with less bureaucracy, wishing to make it more of a federation/confederation.
There is also a third faction thrown in for good measure: the Separatists. One random droid General, who’d basically be space Napoleon, refuses to follow Palpatine’s order to deactivate his droid army, along with some others, and they retreat into the Unknown Regions. The aforementioned general ends up taking over and transforms the CIS into a de facto military dictatorship, and upon seeing the Empire begin to fracture, he and the CIS re-emerge from the shadows to reclaim what they feel is rightfully theirs.
Not only does the Empire have to deal with the two rebel factions, plus the reemerged Separatists, they also have to find Windu, who is now, for all intents and purposes, public enemy number one as far as the Empire is concerned. He is, however, still in hiding and ridiculously hard to find, as he is now on the move, aiming to avoid the Imperial search parties.
There is a couple of other, smaller diversions thrown in for the heck of it, one of them being the survival of Padme. I kinda always thought the whole “losing the will to live” thing was a bit crappy, so I gave Padme a reason to continue living: to raise her child(ren). The twins are still separated, although Leia is in the custody of Padme, who has largely disappeared from the public eye, while Luke, like in canon, is in the custody of Owen and Beru.
Again, it’s a bit all over the place, but at least it’s somewhat original.