that was a good one!; good pun!; what a stinger!
Humorous interjection used to praise a witty remark, especially a pun or sharp retort. Originates from the TV show 笑点, where a cushion (座布団) was awarded for clever answers. The literal meaning 'one zabuton' is the source of the phrase but is not used literally in this expression.
See also: 座布団
A: "The futon blew away!" B: "That was a good one!"
At his pun, I couldn't help but say, "Good pun!"