Nodoka becomes a better person and right away shows, who from now on makes the decisions in the Saotome house.
Ranma beats Ryoga to paste in their first encounter after him endangering other students, almost killing Akane and not feeling any remorse for it. After seeing him getting away with such crap in canon constantly, him finally getting his just punishment is great.
In canon Sailor Mercury is useless in combat early on. Here things are very different. During her first battle, she pulls a Sub-Zero and shock-frosts the Youma in seconds. To top it off, Ranma then shatters the Youma with one precise hit.
Sailor Mars incinerates a Youma in Chapter 8, because of how pissed off she was at the Dark Kingdom invading her home and taking her hostage.
The battle against Neko in Chapter 9 has several moments.
Ranma, drained of almost all his energy and deathly afraid of Neko, overcomes his fear to protect Ami. His love for her become greater than his fear. Him turning away from Neko shatters the demon's invincibility and at the same time protects Ranma from him. Neko of course has a breakdown at that point.
Neko: "No, you can't leave!" ... "Come back!" ... "I... I can't exist without you. You are destroying me!" ... "You can't do this to me! We had a contract, written in blood!"
The Senshi, who up to then had been ineffective, blast away with their magic at Neko, causing him very graphic injuries.
To cap it off, Genma then protects Nodoka from Neko and kills the demon for whose existence he is responsible, by impaling it onto a broken pole.
Akane puts up a really good fight against a Youma, even though in the end she does get overpowered.
A villain example. Jadeite in canon had plans that were always doomed to fail. Here he actually learns from his mistakes and crafts a plan that's very cunning. Graft a mild energy-draining spell onto a music CD, produce it in masses and then use some magic to make sure it's a smash hit. Once circulation it big enough, drain the energy, which due to the wide circulation adds quickly. Due to the small amount drained per person, the Senshi won't notice until it is too late. The best thing? He was able to pull it off perfectly.
Additionally, he did plan to use the inevitable encounter with the Senshi to turn the factory where they would meet into a death-trap. If not for Ranma and Mamoru intervening just in time, the Senshi would have all died in his trap.
Sailor Moon's decision after Beryl had put her through mental torture in Chapter 21.
Sailor Moon: "No, you won't. I will never give in to you. You have failed. I have full trust in my friends that they will manage to free themselves. I'm a Senshi... I'm Sailor Moon. You won't corrupt me or make me give up."
Though it's not that great considering that the whole scene is a big shout-out to the end of "Return of the Jedi."
How Ranma deals with Mikado Sanzenin in Chapter 23. Remembering the canon events, here he takes no shit from the guy, neck-lifting him when he tries to kiss Ami and simply brushing off his attempts at mind-manipulation. To rub salt into it, he outright refuses the challenge to an ice-skate match, saying its a really obvious trap.
Saeko takes apart Picolet Chardin's demand to get one of the Tendo daughters for marriage until he has no chance but to retreat. Bonus points that she doesn't have to lift a finger.
Saeko: "You have no legal basis at all on which you can force anyone to marry you. Any court in France or Japan would laugh you away for the mere idea you could have a legal standing. In case you try to get your way by force it would be kidnapping at least, plus other charges depending on how far you go. So better leave before you embarrass yourself further."
Bonus points for Akane then beating up Chardin after he insulted her on the way out. Pulling his lower lip completely over his head is quite a feat.
Chapter 26: the Saotome males, Soun, Dr. Tofu, Cologne, Mousse and Panthyose Taro banding together to take down Happosai. It works.
Later in the chapter we have the test run of the first Daimon. Ranma disintegrates its head. Even better? The emotion he used to fuel the Ki attack was love. Shows how far the guy has come from his canon personality.
Mamoru proves his mettle in Chapter 27 by destroying a Daimon completely on his own.
Also in Chapter 27, Mistress 9 proves to be quite durable, but a concentrated team effort manages to bring the arrogant being down, though the most awesome is the Silence Glaive finishing her off for good.
Ami against her dark side in Chapter 29. First she does manage to find the inner strength to admit that she does have a dark side as well, thus expelling the parasite from her body. In the physical world, Ami finally wins the fight and literally strangles the physical reprensentation of all the bad things inside herself.
Ami: "You won't hurt them... I promise you that!"
In the whole Nightmares-Arc, it looks like Nehellenia has won, slowly driving her victims to madness in their dreams. She however completely underestimates the power of love, being surprised when the Senshi's friends rescue them. However, the most awesome moment is, when they turn Nehellenia's vanity against her, making her cause her own doom.
Sailor Pluto against Prince Herb. Herb is canonically a beast of a fighter. Pluto however manages to subdue him and teach him a lesson to never again dismiss a woman's skill.