I discovered another year round farmers market in Marin. It's at the Marin Country Mart -- what used to be Larkspur Landing -- apparently kicked off a Farmers' Market at the end of 2010.
It's a much smaller market in comparison with one at the Civic Center, but it was very sweet and not too crowded. Apparently they hand select all the farmers/sellers who are there.
A good seasonal veg selection (I understand they prefer organics, but I saw some nonorganic things too) and I bought some great sustainable textile shopping bags and fresh juice. An interesting mix, and some sellers I hadn't seen before. A found it a happy discovery. Has anyone else been there?