The ninja world of the Naruto universe is one laden with treachery and deceit. With all of the wrongs Konoha has done (even to its own denizens), it is easy for many of the Leaf to consider turning against their village as the fallen Sannin Orochimaru had.
Despite their personal grievances, they remained loyal to the place of their birth, sometimes even taking their suffering to the grave. By analyzing the characters who could have reasonably betrayed Konoha but didn't on account of their integrity, we have a better appreciation for the sacrifices made to keep it alive.
10 Shibi
Shibi Aburame was the father of Shino and the adoptive parent of Torune. When Danzo Shimura required more assassins for his Foundation, he consulted the man and attempted to recruit the former into his organization.
Since none can truly refuse Root's demands though fearful for his son's future, Shibi was forced to relinquish Torune instead in order to placate the villain's needs. He could have realistically turned against the Leaf for what was being expected of him, and he wouldn't have been the first villain that Danzo created. Should Shibi have become a traitor, his backstory would be similar to Kabuto's.
9 Tsunade
Tsunade's obsession with her deceased lover debilitated her immensely. As a consequence of her bond, she often drank herself into a stupor in order to forget the galling loss that she felt in his absence.
Orochimaru volunteered to return him to life through the forbidden jutsu of the Edo Tensei under the stipulation that she heal his arms. As noble as the future Hokage might have perceived herself, she considered the bargain seriously before rejecting his offer. Without the influence of Naruto and Jiraiya, she may have made a different decision.
8 Sakumo
Sakumo was a feared shinobi and frequently regarded as "Konoha's White Fang." Despite the reputation he had acquired for his efficiency, he would die a disgrace to his people on account of a "mistake" he made. Hatake put his allies before the success of a mission - an action considered to be a cardinal sin across the Five Nations.
Unable to live with the disgrace this brought him, he took his own life. However, he could have just as easily visited his vengeance on Konoha for their ungratefulness. Doing so would have rendered him a character much similar to Obito Uchiha - another ninja close to Kakashi's heart.
7 Naruto
Naruto Uzumaki was not always the vaunted champion of the Leaf. Throughout his childhood, he was subjected to frequent ridicule and mockery for the Nine Tails harbored within his body when he wasn't being neglected outright.
This could have bred his animosity toward his hometown, especially since they refused to give him a chance to prove himself. If he had turned against Konoha and became the monster they often accused him of being, his life and backstory would reflect that of Gaara. The diverging choice he made instead would later save the entire shinobi world.
6 Sakura
Sakura Haruno may have usually aligned with the Leaf, but her unhealthy obsession and fealty toward Sasuke Uchiha made her a potential candidate for treachery. She even offered to join him after he had killed Danzo Shimura, only to fail the test he arranged immediately after.
Further, she was willing to manipulate Naruto in order to bring him back and attempted to stave the wrath of the other Konoha 11 shinobi after he already became an international fugitive. With her possessiveness having no conceivable boundaries, the medical ninja could have betrayed her people if her paramour was more charismatic.
5 Itachi
Itachi is an interesting case because, at the beginning of the series, it seemed as if he had betrayed Konoha. The man butchered his own people and attacked the Jonin in broad daylight, nearly kidnapping Naruto alongside his Akatsuki ally, Kisame.
However, this was all in order to preserve global peace since the Uchiha were planning a coup. His willingness to put them down saved an untold amount of lives, though with his sacrifice came a warning to Danzo; should he attempt to harm his brother, there would be grievous consequences.
4 Tobirama
The Second Hokage of the Leaf, Tobirama had just reason to be upset about his older brother's decisions. Having warned him about the Uchihas and what harm they portended on multiple occasions, he would ultimately be proven right by Madara himself after he stole the power of the Nine Tails and used it against the Senju.
Hashirama's poor decision-making would give his sibling leeway to assume control of Konoha's leadership, using his incompetence as a cause for his own ascension. However, he did not repay his brother's folly with treachery - instead, he remained as diligent and steadfast as ever.
3 Sai
There are a multitude of reasons why Sai could plausibly have betrayed the Leaf. His conditioning under the Foundation entailed that he had a difficult time processing his emotions and could not reveal anything about the organization to his friends.
Similarly, Root could have also implanted something inside of him by which to wrangle control of his will and force him to do their bidding. Considering that Danzo's group has betrayed Konoha (aligning with Orochimaru and nearly killing the Third Hokage), this would have made Sai a traitor by proximity.
2 Anko
Anko was the apprentice of Orochimaru and the only survivor of his grueling series of Curse Mark experiments. It granted her a significant boost in power though turned her against her master.
However, she easily could have made a different decision, especially since she might be deemed untrustworthy by the Leaf on account of her bizarre new physiology. Nevertheless, Anko's actions always had Konoha's best interest in mind - even if it would result in her capture at the beginning of the Fourth Ninja War and Orochimaru's subsequent return to the world of the living.
1 Kakashi
Kakashi's may have had more cause to betray the Leaf than anyone else of the entire anime. Its result-oriented philosophy drove his father to suicide, got his friend killed, and nearly forced him to lose touch with his humanity. Worse yet, it compelled Rin to drive his chidori into her chest—as she believed she could not control the Tailed Beast inside her.
Further, he was acquainted with the crimes of Danzo Shimura and aware of his close ties to the heart of the Leaf. This could have jaded him toward Konoha's future, determining the village as irredeemable for its corrupt institutions.