I'm gonna run a quantum universe SWRPG setting where Palpatine accidentally said 'Execute Order 65'.. there is no Palpatine,as he was killed by Windu (and those 3 schmucks who died REALLY quickly in Ep III) and no Darth Vader, as Anakin saw the error of his ways and rejoined the Light Side after the 'Windu Monologue'
It'll be really boring
Not necessarily.
GM Chris of the Order 66 podcast ran an Alternate Universe game back in the days of Saga Edition where Mace and Anakin did cut down Palpatine, so no Order 66 and no Empire. Short version is things didn't get the least bit boring for the PC, and the galaxy had some pretty hefty shake-ups by the time the campaign was concluded, such as one of the PCs inadvertently killing the Big Good of the whole campaign during the climactic starship combat, while the identity of the Big Bad and how they came to be that way caught most of the players by surprise.