The end sequence, where Harry knocks the gun off the coffin, catches it and shoots Dexter while hanging on by the corpse's hand, falls on the car below him, and kills both henchmen, all of this with a gunshot wound in his chest.
Harry: There... All done... Finished.
Harry earned one when he finally got to take down Mr Mustard: at the time, he's tired, bewildered, he's lost a finger and the stitches around it, he's coming down from a demarol high, he doesn't even know where the hell he is, and he's just seen the Girl in the Pink Wig shot dead right before his eyes. And then Mustard realises that Harry is in the room with him, and he's stolen his gun; he's about to unleash a Hannibal Lecture when Harry just shoots him... and continues until Mustard crashes backwards into a coffee table, dead. Then, in an amazing burst of competence, he wipes his fingerprints off his gun and puts it in The Pink-Wigged Girl's hand to make it look like they killed each other in a fight. And all the while, Harry is silent and almost expressionless.
Perry has a ton of moments, but one of the most obvious one is managing to distract Harry's torturer with taunts until he's close enough for Perry to shoot with the faggot gun, which he'd hidden in the crotch of his trousers.