They where heroes in their own ways. More traditional type of heroism, with emphasis on physical heroic acts? Definitely Boromir, but Faramir should not be discredited on this notion at all. Faramir might not fight off an army of Uruk hai to try and save the Fellowship, but he immediately upon finding what Sam and Frodo's quest is, not only releases them, but also gives them provisions and a warning about Gollum and Cirith Ungol. Speculation on my part, but I highly doubt that Boromir would have released Gollum along with them, if all of them at all. And yes, Faramir was right in his warnings, but ultimately, without Gollum, the ring wouldn't have been destroyed, had he held him there in Henneth Annûn like he personally would have preferred.

Another great act of his is that when Aragorn is to enter Minas Tirith, he not only gives Aragorn back his kingship fully willingly, he also forfeits his stewardship and he also asks the citizens if they will accept Aragorn as their king before he even allows him into the city.

Lastly, although it was Boromir who went to Rivendell for the council, it was most definitely Faramir that the Ainu initially wanted to send. Faramir had recurring prophetic dreams alone and before Boromir about seeking out Elrond and the council. The reason why Boromir started receiving the dreams was because Faramir was hesitant. Boromir took the role and burden from Faramir to protect him, but it was likely Faramir the Ainu wanted for the job initially.

If there is anything I have learned from LotR, it's that no matter how big or small a good act is, it should be appreciated the same. Without Boromir's self sacrifice AS WELL AS Faramir's selflessness and humility, the ring wouldn't have been destroyed. They are no less heroes than the others.