Decent ones become available as dropped domains from time to time. The whole dropping domain process is convoluted, gross and benefits big players, but I have seen some decent ones fall through the cracks.
This also goes to show how big the domain aftermarket is - perhaps next time you could list your domains on sites like Dan.com, where they'll renew it for you automatically and help you find buyers who are willing to pay for your domain?
There are good names that sell all the time. You just need to catch them or use a backorder service like namejet, dropcatch, etc.