When Alan comes home from talking to his boss, Eric runs up the stairs. You can see him turn around at the top because, according to DVD commentary, the stairs end abrubtly.
Eric: Did you get my five percent back?
Alan: No, Eric. I didn't.
Eric: I'm gonna go cancel five percent of my dates.
Shawn: So this guy I play is like, what, a warrior and a hero?
Mr. Feeny: No, this guy you play has very few lines to memorize.
Cory: You know, maybe if Hamlet had worn pants he could have made a decision or two.
Topanga: Is that a sexist comment.
Cory: That's what I was shooting for.
Mr. Feeny: Now this is a tricky part to cast. Hamlet gets on a lot of people's nerves. He makes one stupid mistake after another and for five acts he never shuts up!
(everyone looks at Cory who isn't paying attention)
Cory: What, do I have a booger?
Cory: All this Hamlet guy does is talk! He even talks when no one is there!
Shawn (about Topanga): Don't listen to her Cor; her dad sews.
Minkus (to Shawn and Cory): Thou speaketh true.
Shawn: Thou speaketh like thnaggleputh.
Episode Title: The Play's the Thing
This title is a direct quote from Shakespeare's play, Hamlet. The entire quote reads, "The play's the thing wherein I'll catch the conscience of the King."