He gets a Determinator moment with Porlock, proves himself a decent-enough tracker and a capable actor, delivers a Badass Boast to a prisoner while playing the Deadly Doctor trope straight, and rides halfway through London on a Cool Horse (Moran's uncooperative stallion, no less!).
In fact, Holmes can hardly believe it when Watson tells him just a portion of it.
And when Watson seesDeath, he refuses to let him take Holmes.
Moran, of all people, gets his own Crowning Moment of Awesome. All chapters previous, he has been subservient to and rather afraid of Professor Moriarty, and, now, after refusing to shoot Holmes on Christmas Eve, he not only stands up to Moriarty (and works out that the Irregulars are the men defending 221B) - he also delivers a brilliant comeback at the Professor's mockery.
Moriarty: "And what does that make you, Colonel? A soldier with a heart?"
Moran: "I hope so, sir. It would be deucedly difficult to live without one."
Every time Lestrade or Gregson give Patterson what-for. The fact that Patterson is Good Is Not Nice Incarnate makes such moments deliciously satisfying.
The face-off between Moriarty and Mycroft at the end. There's worlds of subtext in their brevity.
Holmes in his Let's Get Dangerous mode in the chase scene. Doesn't get much more awesome than a convalescent Sherlock Holmes shooting at Colonel Moran in a cab chase!
One-Shots
"Day 18: Long Time Falling" depicts the life of Professor Moriarty and the fight at the Reichenbach Falls with metaphors supplied by two different poems. At the end, Moriarty seems to regard Holmes's (simply called "the boy") victory as the detective's Crowning Moment of Awesome.
Mary's Dying Moment of Awesome in "Those Dark Hours" - she shoots down several Mooks before being shot down by the last one. Word Of God says that the idea came from the second season of Jericho.