I bought a couple of sets of the Sennheiser Model HD-202. It seems that I purchased 1 set from EBay, and another from a Yahoo seller. (About $30 shipped, if I remember correctly)

They are pretty efficient, as I use one set with a little Sony walkman when I ride around mowing the lawn.
I saw a thread much the same as yours, where they recommended them highly. I'm not really into high end headphones, so others may have better ideas.
Good Luck
