The fight between The Axe Gang and The Three Masters. The intro showed the Axe Gang to be an unstoppable force. When the gang appears at Pig Sty Alley after Sing's antics, they prepare to set a woman and a child on fire. Coolie saves the pair by catching the lighter, then singlehandedly takes on the gang. When it appears that Coolie might be in over his head, Tailor, who had been shown to be a effeminate sissy, rips off his shirt, revealing his well-built form, and lends Coolie an assist. When the Axe Gang members go for their guns, Donut uses his kneading staffs to disarm them and destroy their weapons. As a result, Coolie, Tailor, and Donut deliver a Curb-Stomp Battle to the Axe Gang and send those that weren't knocked out running.
Badass GrandpaThe Beast and the middle-aged Battle Couple are tangled up like a human pretzel. Gangster-Boss Brother Sum tells Sing to hit the couple with a railing post and help the Beast. Sing gets pissed and hits Brother Sum, who screams like a little girl. That's the Awesome. Then Sing, who all movie long has been pretty much a Minion with an F in Evil proceeds to hit THE BEAST with the railing post. That's the Heartwarming. The Beast comes close to a literal Curbstomp Battle with Sing, let's call it a Floor Stomp instead. Point is, Sing is beaten to near-death. With tragic music playing. That's your Tear Jerker. The Beast asks "Why did you hit me?" Sing's response? To fumble for a tiny little stick off the floor... and hit him in the head AGAIN. That's the Funny. The Beast then smashes Sing's face into pulp. Don't fret though, he gets better.
The final fight between Sing and The Beast. All around awesome, but especially the finisher, where Sing gets thrown high up into the air, through the clouds, and he then sees a cloud that looks like Buddha. He then starts falling down, his shirt accurately starts burning up, and he stops falling just before he slams into The Beast. His shirt, in tatters, falls off his body, and The Beats is slammed into the ground so deep that there is a crater formed. A crater shaped like Buddha's Palm.
Even better, the beast's response to this? He tiredly stands up... then bows down and screams, MASTER!
The fight between Donut and Tailor and the two Musical Assassins. Though it's also tragic due to Donut, Tailor and Coolie's deaths, it's also one of the most awesome fight scenes in the movie and the only scene where you're missing out if you aren't watching it in surround sound (or at least a good pair of headphones.)