The opening sequence in which Porter cons $3 (that he took from a beggar's hat) into a nice suit, a Mag, and a steak dinner.
Hell, the entire movie is a moment of awesome for Porter. While he does get the shit beat out of him quite often, he more than makes up for it by almost always coming out on top! By the end of the movie, he's not only framed the two corrupt cops, he's also gotten that Stegman worm killed, his traitorous partner killed, and also managed to almost systematically severely weaken the Outfit by killing its three main leaders...and all because he was conned out of $70,00 dollars (an amount that's pretty measly as most people point out) .
More Porter Awesome, when he hitches a cab he finds out that Stegman was already in the cab waiting for him at gunpoint. As they ride in the cab, Stegman is unbelievably smug, claiming how he'll turn Porter in for a huge reward while still holding the gun. What does Porter do? He simply grabs the gun from Stegman's hands mid lecture. Porter's face after he does so is priceless.