The only paid ones we do are bbonline, local association, a wedding directory and a local state B&B directory (only because it didn't cost much)
We dropped bandb.com (tired of the price increases and other hassles) and the local chambers this year (one didn't perform at all, one was giving free banner ads and plugging a new local HOTEL that touts itself as a b&b, but they weren't plugging any of the local B&B's when we were paying for the service! ).
The rest of our listings are free. Not planning on any new listings.
We currently use Resnexus/Sam's for merchant services.
According to our stats, google and our local VCB far out perform any paid directory listings and we do get most of our bookings from those two sources. I really think aTripadvisor link would be the next thing...I'd guess it would probably be in the top three if we added it..