Source: Anchorman: The Legend of Ron Burgundy
Speaker: Ron Burgundy
I'm in a glass case of emotion!
Context
This line is spoken by Ron Burgundy, played by Will Ferrell, in Anchorman: The Legend of Ron Burgundy, directed by Adam McKay (2004).
When Ron Burgundy chucks a burrito out his car window and hits a motorcyclist (Jack Black), he doesn't know what he's in for. In retaliation, the biker kicks Burgundy's dog, Baxter, off a bridge. Bye bye, Baxter.
Overwhelmed by emotion, Burgundy uses a pay phone to call his friend Brian Fantana (everyone's favorite person, Paul Rudd), but he can't make any coherent noises because of all the wailing. When Fantana asks where Ron is, he wails, "I'm in a glass case of emotion!" which is a fairly accurate description of the contraption and mental state he's in.
Where you've heard it
You've heard this quote whenever someone is upset for any reason—whether it's because their favorite TV character got killed off or because they made the mistake of seeing Anchorman 2.