Saitou and Okita crossing swords for the first time. Their mutual joy in finding an opponent who presents a real challenge is so fierce that it takes Hijikata, Harada, Nagakura, and Heisuke to physically separate them.
Saitou revealing that he only pretended to betray the Shinsengumi.
Hijikata's furious speech when he confronts Kazama after the battle of Toba-Fushimi and finally hits the Rage Breaking Point:
"So I'm not a real demon? Why the hell should I care? Never once in my whole stinking life have they treated me like a real warrior. But hell... where are you supposed to find a real warrior these days? Lotta men calling themselves 'samurai' when all they do is sit behind ten feet of stone in a castle and get fat. Only thing those sons of bitches care about is making sure the side they buddy up to is the side that's gonna win. We're better soldiers than any of those bastards! I believe what I believe. Nothing can change that. And I will never, ever retreat. That's what's brought us this far. Call us fake if you want, but if we push hard enough and don't give up, eventually we become what we say we are. If I can defeat you now, as a fury, then I - no, then we - can become real demons. Right?"
Hijikata at the Battle of Utsunomiya Castle. With the soldiers he's leading demoralized and on the verge of fleeing, Hijikata charges into battle alone. Watching him lay waste to the enemy gives the other soldiers the courage to follow him, resulting in a rare victory for the shogunate troops.
Chizuru saves Sanosuke by taking a bullet in his route.
When Inoue is killed by Imperial soldiers, an absolutely furious Chizuru draws her kodachi and charges them...then gets shot by multiple bullets. Cue her Healing Factor kicking in as she slowly stands up. The soldiers freak out and shoot her again, and she still refuses to go down!
The battle scenes in The Movie are gorgeous. Of special note is the swordfight between Kaoru and Okita in Kyoto Ranbu, after the latter's transformation into a fury - Okita comes within inches of killing Kaoru outright, twice. His opening move slashes Kaoru's throat and probably would have been lethal were Kaoru not a demon, and Okita follows up by cutting completely through the support post of a nearby building before ramming his sword through Kaoru's shoulder and the wall behind him, pinning him there. Kaoru survives only thanks to having prepared a last-ditch dirty trick in advance.
Also in the first movie, Hijikata's Badass Boast to Kazama during the demons' attack on Shinsengumi headquarters, when Kazama demands that Chizuru join him because demons don't belong among humans:
Hijikata: You stand in the house of the Wolves of Mibu! There are no "humans" here in the first place!