The extended duel between Shu Lien and Jen, with Shu Lien expending every item on her Wall of Weapons against the Green Destiny. At one point Shu Lien grabs an oversized cudgel that she can barely keep off the floor. And Jen waits for her to find something else before they continue.
Jen utterly thrashing one of the men who confronted her at the resturant simply because his name was the same as her fiance who she cares nothing for.
Even better is the mass 'aaah' of comprehension when Li and Shu Lien explains to the beaten and confused men that Jen was set off by the name of her husband.
Not to mention to collapsing staircase that punctuates the end of Jen's 'why I'm so awesome' speech.
According to Ang Lee's commentary, one of the guys' names is hilarious if you speak Mandarin, for how long and redundant it is.