Jack Ryan's foiling of the assassination attempt in the beginning of the book is acknowledged in-universe.
Later, he scares the piss out of the psychopath who's been gunning for him in the whole book, and Sergeant Major Breckenridge gets a CMOA for making sure Jack doesn't cross the Moral Event Horizon.
The climactic boat chase at the end of the movie.
Ryan singlehandedly disarming Miller and the other terrorists who attack the royal family, taking a bullet in the shoulder for his troubles.
Ryan and Robbie picking off the terrorists in Ryan's house in what becomes a game of cat and mouse.
Inspector Robert Highland; as he and his colleagues are rounded up to be killed when O'Donnell frees Miller, he is questioned on his "betrayal" towards his people. Instead of begging for his life, he simply retorts with this before he and his men are executed:
Highland: Get on with it and be on your way.
Ryan's keen sense allows him to pick up on Ned Sterling's intentions when the latter is waiting outside the academy gates to have him killed, and when the moment presents itself Jack attempts to disarm him. He still needs to be saved by the academy guards, but nevertheless puts up a good fight before they intervene.
Ryan swearing to destroy Paddy O'Neill's IRA right to his face for refusing to aid him in finding the real culprits who attacked his family. In an Irish pub, no less.
Ryan's Eureka Moment when Paddy O'Neill presents him with a lead on O'Donnell's girlfriend Annette, who happens to be British. Marty doesn't feel the evidence is reliable until:
Marty: You tell him you're looking for a girl, he gives you pictures of a girl. He obliges you to get you off his back and you believe him?!
Ryan: ......I never told him I was looking for a girl, Marty.