Jake Sully from Avatar is not always heroic, but he is always courageous. He chooses to move to Pandora, to take his brother’s place in a program he knows very little about. He travels light years away for a change, something to get him out of the grief of losing the use of his legs, and the grief of losing his brother. He adapts quickly to the avatar body, and he’s barely on the planet before he’s on a mission into the jungle, where he’s then separated from EVERYTHING he knows and is forced to live on his training. Part of his drive is to prove he can. The scene where he’s first in his avatar body, where he can run and feel free again, is my favorite in the whole movie. This drive carries over to his determination to learn how to ride that horse-like creature, and then the Banshee.
What makes him courageous is his choices. He chooses to learn more about the Na’vi, though he doesn’t speak their language or know anything about the planet. That he chooses to share this information with the headcase mercenary is a problem, but one motivated by the desire for the surgery to give him back the use of his legs. When he realizes the extent of his mistake, he takes every chance to make it right, starting with telling the truth to the Na’vi , which isn’t received well. (Who can blame them?) Then he risks his life to stop the mercenaries from getting what they want. Despite the rejection of the Na’vi, he does everything in his power, including leaping onto the back of the Taruk, the biggest, baddest Banshee, because he knows he has to have some power behind him when he unites the tribes against the humans.
Sometimes his courage makes him think before he acts, so he follows his heart. Sometimes it gets him in trouble, but in the end, it leads him to do the right thing.