In Gardens of the Moon when the freed Jaghut tyrant is trapped inside Kruppe's dream and despite his immense power can't do about this, he asks "What kind of game is it?". Answer: "Why, of course, Kruppe's game." is awesome.
Before that Raest, the Jaghut tyrant in question, fights against five dragons on his way to the city of Darujistan, including an Elder Dragon. The battle is interrupted by Kruppe, though it's clear Raest would have won regardless.
Ganoes Paran summoning, manhandling then using a freaking God as bait to free two hounds of shadow from within Anomander Rake's sword. Doubly awesome since said God had been using him as a pawn throughout the book.
Anomander Rake not fighting the Jaghut tyrant was very much a letdown, considering how much their confrontation had been built up. His subsequent curb stomping of a greater demon during the citywide battle at the end of the book almost made up for it.]]
Roach, just Roach. This is the pampered Noble LAP DOG first seen in Dead House gates that not only survived Coltaines march and became the Alpha dog of the starving mutts on said march, but the little rat JUST WON'T DIE.
The demon Apt rescuing 1,300 crucified Malazan children in the space of a single night without anyone noticing they were gone until morning. Okay, so Shadowthrone plans to turn them all into Tyke Bombs, but still...
Coltaine's shepherding of 30,000 Malazan refugees across the Holy Desert Raraku is one long string of CMOA's for everyone involved. However, one particular example springs to mind.
The refugee's path is blocked by a river and an enemy army is closing in on them swiftly from behind. Eventually they find a place to ford it but the water is so deep it'll slow them down enough for the enemy to catch up. In addition, another enemy army is approaching on the other side of the river to cut them off. What do Coltaine's sappers do? They build an underwater road, allowing the refugees to pass over quickly enough to escape certain death.
And when the enemy army tries to cross over after them, it turns out the sappers rigged the road with explosives. Cue massive explosion destroying a large amount of enemy fighters.
One of the most badass lines in the series comes in the first chapter. When Fiddler, Kalam, Crokus and Apsalar are crossing the Kansu Sea, they run into a Soletaken dhenrabi...
Soletaken: Another fishing boat lost at sea. Alas.
*Fiddler blows it up with a cusser*
Fiddler: You picked the wrong fisherman.
Memories Of Ice
The opening of the book. Three gods show up to curse Kallor, for being the kind of monster who destroyed an entire continent. And what does our all-too human psychopath do? He curses them back. And it works! And that's following his surival of a continent catching on fire. Why did it catch on fire? Because he was so evil his people summoned a foreign god and dropped it on the continent in an attempt to kill him. They ended up killing everyone but him. Kallor is a monster, there's no doubt about that, but damn.
Gruntle ascending to the position of Trake's Mortal Sword, gathering together a ramshackle militia, then proceeding to absolutely serve the elite Pannion infantry invading Capustan. When forced to retreat into a nearby building, they kill so many invaders whilst retreating floor-by-floor that from the outside it looks as if the building itself is bleeding.
The siege of Coral. Panion's soldiers, Bridgeburners, undead K'chain Che'malle, Lady Envy and her Seguleh's, Tiste Andii and their awesome flying fortress, The First Sword of Imass, Shield Anvil Itkovian... Probably the most awesome chapters of entire series.
One of the greatest moments was the revelation of where Anomander Rake had hidden Moon's Spawn, his flying fortress. When the battle seems lost, the massive basalt construction rises out of the sea, then crushes the Pannion Seer's keep by literally bulldozing its way through Coral.
Karsa Orlong (a giant Boisterous Bruiser/ Blood Knight) beats a Hound of Darkness (bear-sized Hounds that were the precursors to the Hounds of Shadow) to death with his bare-hands. He then chases a second one down and attacks and kills the other one, getting mad when Leoman of the Flails helps kill the Hound. For reference, two Hounds of Darkness were able to easily fight off and possibly kill five demons capable of killing hundreds of humans in a matter of minutes.
Towards the end, when the Edur have mostly won, their emperor meets the king's magician:
The Edur in the centre of the row spoke. 'Ceda Kuru Qan. The kingdom you serve has fallen. Step aside. The emperor wishes to claim his throne.'
'Fallen?' The Ceda's voice was thin in comparison, almost quavering. 'Relevant? Not in the least.'
Brys vs. Rhulad. Seriously, it wasn't sword duel - it was surgical operation.
Kalam, Tavore and T'amber fighting their way out of the Malaz City with SIX HUNDRED Claws on their tail the whole time. Probably some of the best fight scenes Erikson has ever written. And Kalam and Tavore survive.
Toll the Hounds
The two duels at the climax of Toll the Hounds. Annomander Rake vs Dassem Ultor is awesome enough although diluted somewhat by Rake letting himself lose, but the truly impressive match is the sideshow: Kallor vs Spinnock Durav, one of Rake's Tiste Andii. Rake has ordered Durav to prevent Kallor from entering the city no matter what the cost, and Durav, with nothing but his stubborness and sense of obligation to his master manages to hold Kallor back for an entire night, despite getting cut to pieces in the process. He doesn't even manage to scratch Kallor, yet his sheer determination is awe-inspiring. Kallor himself gets his shortly afterwards, when Orfantal, a freakin' dragon, swoops in and carries him off in revenge for the death of his sister's lover. Kallor's response? He stabs Orfantal in the head, causing them both to crash. And survives. That chain of events alone made Toll the Hounds worth buying for me.
Rake sacrificing himself to force his mother, an Elder God to stop ignoring her people, and in the process also saves the entire world. At the same time he asks his mortal enemy for forgiveness for trapping him in his sword for thousands of years:
"You ask my forgiveness? When you unravel what I have done, what I did so long ago? When you heal what I wounded, when you mend what I broke?' He raised his voice to a shout. 'Rake! There is no forgiveness you must seek - not form me, gods below, not from any of us"
The Crippled God
Hood showing up out of nowhere and taking a bite out of a Forkrul Assail's face.