C-3PO, thanks to his skills as an interpreter, provides a rough Basic-Keshiri dictionary without having come into contact with the language before. Think about it: without having any idea of syntax or grammar, Threepio cracks a language from a recording.
In the opening of Apocalypse, the Jedi manage to simultaneously assassinate hundreds of high ranking Sith with a number of ingenious and perfectly timed plots. All part of Luke's Batman Gambit, one which he pulled on the entire Lost Tribe.
Saba defeating an Abeloth avatar in hand to hand combat by biting its head off.
Grand LordVol and Abeloth's mental duel, which ends with Vol fending off Abeloth's Mind Rape with his own brand, making her retreat in pain. That's right, Vol's so powerful that he can Mind RapeAbeloth.
Mirax Horn's Mama Bear moment - Colonel Wruq Retk has hung her children, frozen in carbonite in response to them succumbing to a form of madness making them see everyone but those similarly affected as imposters, like trophies in his office. Her response to this is to knock him unconscious. To highlight this, Retk is a Yaka, about two meters tall, and with a body frame to match. Mirax is a little over one and a half meters and, though married to a Jedi and mother to two, isn't a Force user. And all it takes is one punch to send Retk to the ground. Do NOT mess with her children.
Luke, Jaina, Vestara, and Ben against ten Sith on Ziost, a world very strong in the Dark Side, meaning that all of the Sith are stronger and the Jedi weaker. Luke and his party-including Ben going up against three Sith Sabers at once-win without too much trouble.
Luke and the Hidden One, head of another Force-using organization, get into an epic Force duel, and Luke wins. Really, "Fate of the Jedi" could be renamed the "Luke Skywalker Is A Memetic Badass" series, although "Fate Of The Jedi" is probably easier to sell.
Luke Skywalker achieves the pinnacle of his badassery: He and Darth Krayt go up against Abeloth (a being who it previously took the Daughter and Son working together to beat) by Mind-Walking, and defeat her in hand-to-hand combat. Even when Krayt inevitably turns on him, Luke still wins.