Akakabuto's last stand is quite epic. Dude just can't die.
Cross, while pregnant, crossing a sea to get a message to Gin.
Gin defeating Sniper, complete with the show's theme song playing as battle music.
Ben, while going blind, scoring first blood against Akakabuto.
Even if it didn't really do anything, Daisuke ramping off a snowbank to crash his snowmobile into Akakabuto was pretty awesome. How many people can claim they've throat-punched a bear with a snowmobile?
Gin throwing John on his back, momentarily defeating him, accompanied by a shocked face from Daisuke. Perhaps even more so in the manga where John is seriously pissed for being flipped by a puppy.
Riki and John's fight in the manga (which is only mentioned in the anime). Riki defeats the cocky John in a single strike, to which John narrates how "I didn't even feel him touching me..!"
Kurojaki, after fighting off even Ben and Moss is challenged by Gin, having told Akame he wants to prove himself worthy of Ben's plans to make him the new leader. The result is him flawlessly defeating Kurojaki while images of his father fighting Akakabuto pans over him.