I use Craigslist regularly. It's pretty popular in my city. One thing I've learned is to ignore the outrageous low-ballers because nothing good will come of it. The only other free option that I know of is listing something in the community paper. Maybe you have one of those too.
We have bought some used household items from Craigslist, but that was several years ago already. Now, we like to browse Facebook's marketplace to see what's near us for sale. I wonder how Craigslist is doing in light of all the other free places to post ads these days.