I would rather fight for Brutus' side. Although many of the conspirators did act out of jealsousy and vengence, Caesar was overly power hungry and needed to be stopped. His attack and killing of Pompei alone proves this, not to mention his fainting behaviors after the citizens cheered when he turned down the crown. I wouldn't be happy about being teamed up with Cassius, but being that Brutus was the most respected, he would be the won in charge if his side one, and I'd be satisfied living in a country with Brutus as leader. He seems to have learned a little bit more about Cassius by Act IV, and I don't think he would be so naive to fall for any more of Cassius' rhetoric.
I don't see Antony as an honorable man. It seems he used Caesar's death as a way to come out of Caesar's shadow to emerge in a more powerful position. He simply used his friend's death to gain sympathy, justify his actions, and further his career. His eagerness to double cross Lepidus and his decision to change Caesar's will to benefit himself shows he has little loyalty for Caesar. Beyond the play, he had a relationship with Cleopatra, Caesar's former mistress, which also shows a lack of respect for Caesar.
Octavius did prove to be a solid leader for Rome, but not before putting Rome through a third bloody civil war in a row with his battles with Antony. If Brutus' side would have won, I think it would have ended the war for good, and the people would have almost unanimously chosen Brutus as the leader. In this state, Rome would have been a great place.
I'm not sure I could pick, either. The conspirators are not good people--filled with lust, jealousy, ambition, and anger. Brutus is their victim as much as Caesar is, although he does not immediately die from it.
Antony is honorable, but his and Octavius' behavior toward Lepidus is less than noble.
As with any group of humans, there are flaws. You end up choosing the lesser of two evils...it's a lot like an election year!
Since Octavius Caesar is the adopted son of Julius Caesar, and since he restored the Roman Empire and ruled much more democratically than many thought he would after his victory, I would choose to stay with Octavius.
I don't think I could pick. It's not as if either side is clearly morally superior to the other.
I sympathize with Antony because of what he says at Caesar's funeral. He seems like a sincere person who deplores this assassination. I agree with him on that -- I think Caesar shouldn't have been killed.
But it is not as though Brutus is evil. Antony himself says Brutus is the most noble of the Romans. He didn't kill Caesar out of greed and ambition, so it's not like he's Macbeth or someone like that.
I can't really pick because there's no clear "good guys and bad guys" here.