What an intriguing question! My sympathies now lie with the victim, but when I first read the play in high school, they lay with the conspirators. My use of "conspirators" might be a giveaway: because of the REAL, not literary, conspiracies daily reported in our media -- conspiracies to gut governments, to defraud the innocent, to become profit from misery by selling drugs, to destroy nations and/or religions, to bilk the unwary -- I now view conspiracies in an exceedingly negative light. In my youth, I considered the plotters to be brave rebels, seeking only a better life for the people of Rome, men willing to risk their own lives for the good of the people. History proved me wrong, had I bothered to read it at the time; the triumvirates were just as corrupt as was Julius Caesar, and there was no perceptible improvement in the life of the common Roman, although Rome did get to smack down Egypt -- a project which Julius Caesar had begun.
These days, I find myself sympathizing with Caesar: if he WAS corrupt, he was the product of a corrupt society. If he WAS a tyrant, he was CHOSEN to be one. Corrupt or not, tyrant or not, he was a man who trusted his friends. He trusted those who had helped him to achieve his position in the first place. Since his writings indicate that he was a man of intelligence and erudition, with a grasp of politics and history, I deem him much more deserving of sympathy now than I did when I simply accepted the conspirators' assertions that he was unfit to rule.