Max and his Jamie Dimon as a tapeworm is my favorite. I remember seeing the episode when it first aired and having to pause it for a full 5 minutes so I could stop laughing.
Also rate the Ron Paul exchanges with Bernanke
Then there is Matt Tiabbi's classic depiction of Goldman Sachs as a "great vampire squid wrapped around the face of humanity, relentlessly jamming its blood funnel into anything that smells like money".