Response to a riot

• Sound of feigned amusement
• Sounds of hearty laughter
• "That's a riot"
• "That's rich!"
• "Oh, yeah, very funny!"
• "Ver-r-ry funny!"
• Desired response to a 3-Down
• "The Merry Old Land of Oz" opening words
• "You think you're so funny!"

Wiktionary Word definitions in Wiktionary
interj. haha; a laugh