What is the quickest way to review a sorted list of all unique values of a variable?

Click the Values/Stats button in the Variable specifications dialog box to display a sorted list of all unique numeric values and corresponding text labels (if there are any) for that variable. The Variable specifications dialog is accessed by double-clicking the variable name in the spreadsheet. See What is the quickest way to review basic descriptive statistics for a variable? for further details on this dialog box.