Ebay or stubhub are good ways to go.
Or, the message board, like you are doing now.
If you need just a single, stubhub is a very good route to go.
I am probably going to sell my tickets to the Colts, but that appears to be premium game in terms of selling on ebay with what I have done in the past.
I have 6 seats, Section 118, three rows from the field, and on the aisle.
Let me know if you are interested.