Question

what is the best way to punctuate the pause in the sentence below?
after i pick a book usually a mystery or adventure story i really enjoy curling up on the easy chair.
after i pick a book usually a mystery or adventure story i really enjoy, curling up on the easy chair.
after i pick a book . . . usually a mystery or adventure story . . . i really enjoy curling up on the easy chair.
after i pick a book—usually a mystery or adventure story i really enjoy curling up on the easy chair.
after i pick a book—usually a mystery or adventure story—i really enjoy curling up on the easy chair.

Explanation:

The phrase "usually a mystery or adventure story" is a parenthetical aside that adds extra information about the book. Em dashes are the correct punctuation here to set off this non-essential clause, clearly marking the pause and separating the aside from the main sentence structure. The other options either misplace commas, use ellipses (which indicate omitted text, not a pause for an aside), or only use one em dash, leaving the parenthetical phrase incorrectly integrated.

Answer:

After I pick a book—usually a mystery or adventure story—I really enjoy curling up on the easy chair.