In terms of results, Antony's speech is the more effective one. He sways the crowd to his side, encourages them to riot against Brutus and the other conspirators, and presents himself as Caesar's avenger.
While Brutus approaches his speech with logic--he tells the truth about his part in and motivation for the assassination of Caesar--he neglects to use the persuasive appeal of pathos (an appeal to emotion) effectively. In contrast, Antony employs pathos to an extreme because he realizes that the context of his speech (Caesar's funeral) calls for it. He gets the people to remember all that Caesar had done for them. He goes down into the crowd which not only establishes his credibility as being one of them but also stirs up their emotions for him.Â He tantalizes them with the reading of the will, and most effectively, he uses irony to point out Brutus's hypocrisy in killing Caesar (his repetition of "and Brutus is an honorable man").
If Brutus had not given Antony the advantage of speaking last or imposed the other stipulations upon Antony (speaking from the same place and saying only good things about the conspirators) perhaps his speech itself would have been able to win the crowd, but Antony masterfully incorporates all of Brutus's "rules" in his speech and uses them to his fullest advantage.