The whole ale-making town banding together to try to get the sword out of ground. Granted they can't manage but it's still a worthy effort nonetheless. Followed nicely by Meliodas pulling it out to give the town back its water flow.
Ban's escape from Baste Dungeon; up till then he's been willingly allowing them to hold him in prison, even letting them pin him to the wall with stakes and chains. When he hears Meliodas and Diane are fighting outside, he frees himself and kicks the cell door open. Apprentice Knight Jericho tries to stop him only for Ban to dodge every slash in such a way that not only does he come out unscathed, it cuts off his beard and gives him a haircut.
Elizabeth walks into a cloud of bugs to save a child caught in it, but the child turns out to be an illusion made by one of the Holy Knights and tries to beat her to death while gloating. He stops to reveal what caused his power, the bell in his staff, only to find it gone. Elizabeth smirks and spits it out of her mouth. With the bell gone, the spell that was causing Meliodas and Diane to see each other as said Holy Knight breaks and they promptly save Elizabeth and hand the asses back to the Holy Knights who were attacking them.
Pretty much anytime King fights. He managed to find a way to subvert Ban's immortality and completely owns Guila throughout their match when even Meliodas, Diane and Ban were having trouble with her.
Meliodas likewise gets one at the end of the fight as Guila had figured out how his power works by limiting her explosions so it won't harm her when he deflects it back at him and taking advantage of the opening it brings. After King gets involved and curb stomps her, she loses composure and tries to attack him with a full force explosion. Only for Meliodas to rush in and reflect the blast back at her, beating her.
Ban vs Meliodas during the fighting festival. Both of them go all out, with both of them using techniques that would probably kill normal people.
After the Tournament two holy knights, including a stronger Guila, attack the sins, with Guila defeating Meliodas, and the other defeating Ban. Then, King, with the help of his sacred treasure, effortlessly curb stomps both of the holy knights in only a few seconds. This, more than anything, demonstrates the difference in power between a sin with his sacred instrument, and a sin without it.
When Meliodas went into his dark mode he easy defeated Guila and Jericho without a Sacred Treasure and overwhelming Helbram who has the power of 20 Holy Knights and even took Hendricksen to make Helbram borrow a little bit of his power.
Diane shows just how powerful she can be with her sacred treasure Gideon by throwing a small mountain on top of the holy knight who injured Meliodas.
Meliodas shows how strong he really is by using a twig to cut a mountain in half and use a real sword to slay a beast in many pieces.
When Elizabeth give Meliodas Liz's sword, he used it to kill the Armor Giant by slashing it into three pieces, but then cut into many tiny pieces instead.
When Elizabeth was kidnapped by a unknown Holy Knight, instead of running toward Liones, Meliodas ordered Diane to toss him along with Ban and Gowther to Liones in a quick way.
After landing in Liones, a bunch of Holy Knights used several attacks on them, Meliodas just used Full Counter and defeated six Holy Knights with ease and still continued to defeat the others while rushing in.
While in prison, Hawk wanted to use the toilet so badly that he break through a iron door and defeated a knight while protecting Elizabeth.
Everything about the fight between King and Helbram. It seems King has been holding out on us...
In chapter 81, the freed Gilthunder chops off Hendricksen's hand to save Meliodas.
Not to mention that Meliodas was fighting against three Great Holy Knight class powers at the same time.
King Arthur, due to being able to embody Badass Normal by Going head to head with Hendrickson with no holy knight powers of his own. Let me repeat: He has no special magic or powers, he's just a really, incredibly skilled swordsman.
Merlin curbstomping her former apprentice, Vivian, who is said to be strongest mage in Leones.
In Episode 23 of the anime, Elizabeth finally unleashes her true power, which had been hinted at throughout the series. Not only does she manage to damage Hendricksen, who had been shown to be virtually invulnerable up until that point, but she manages to heal the wounds of every living Holy Knight on the field and every citizen of the city of Liones.
Chapter 135: Meliodas regains his true powers that was sealed and kept safe by the druids and shows why he is the strongest of the Sins by calmly wiping Galan's ass within 10 seconds, with time to spare issuing a threat to the Ten Commandments. All his fights prior to this, even against the demonified Hendrickson, was him being severely handicapped and was just a minuscule fraction of his true powers.
Ban starts handing Galan his ass by stealing his powers and using them against him until the second of the Ten Commandments interfered.
Escanor, when wielding his axe is so terrifyingly powerful that Galan chooses to run away even though he knew that he'd be turned to stone by his own power. And in the very next chapter, his soul is so powerful it destroys another Commandment who tried eating him.
King unleashes his true power against the Fairy Doll of the first Fairy King and obliterates it, while Diane's golems of her friends manage to defeat Dolor's. Even if it was a hard fight, they both managed to do an amazing job.
During the Escanor fight (since this is night, his power is at his lowest) against his comrade Gowther, He is subjected to Mind Rape where his Dark and Troubled Past is revealed, and how he become infatuated with Merlin. But he managed to not only break away from the Mind Rape, but use his love for Merlin to transform into his noon form at will. Cue Badass Boast.
And then what does he do to Gowther? Nothing at all. Instead, he directs his strongest attack at Dolor and Gloxinia, using his battle with Gowther as a distraction, and reduces them to a couple of charred, twitching heaps on the ground. Oh, and the kicker? Since it's still night and it's a voluntary transformation that only lasts a few seconds, Escanor doesn't have the same power his "real" noon form has, even when releasing his Sacred Treasure. And he still strikes down two more Commandments!.
And the awesomeness continues! Escanor is powerless after the transformation recedes, and Dolor starts getting up, so Meliodas takes over the fight. Cue a complete Curb-Stomp Battle that makes even Ban shiver at Meliodas's new powers, and when Gloxinia gets up covered in armor after Dolor is defeated, the armor is instantly destroyed by Meliodas's Demon form.
The battle rages on, with Meliodas showing us again why he's so feared and respected as the strongest Sin. He continues to utterly curb-stomp two Commandments, while also being clever enough to fight them one at a time.
And just when you think the fight was over, The other Commandments crash the fight. Bonus points to Merascylla, who survived being burnt out by Escanor, despite being all charred and disconfigured.
Even when getting pummeled, Meliodas is still completely badass. He's fighting 9 Commandments at the same time, and holding his own quite well, specially considering that, earlier, he and the other sins were getting curbstomped by only one Commandment. That is, until his arm gets chopped off and his demon power recedes, but even then, he just holds his sword in his mouth and shows that he still won't give up!!.
Ban sneaks up on the Ten Commandments by suppressing his presence and then snaps the neck of the soul-stealing one before ripping out a bunch of their hearts with his "Fox Hunt" technique to save Meliodas.