Steeleye Span's "Please to the King" and "Below the Salt" - among the greatest albums ever recorded in any popular genre.

Also treasured: the Folktrax CDs of 19th century shantymen, even if you can't understand half of what they're singing!

Close to the top is Judy Collins's "Maid of Constant Sorrow."

Cash value of all five together, used: maybe forty bucks. Sentimental value: priceless.