I've used Lemonstand for a few projects and really enjoy working with it. There are a few features it's lacking still (no gift certificates, no faceted search)

I've used Lemonstand for a few projects and really enjoy working with it. There are a few features it's lacking still (no gift certificates, no faceted search) but it's a very flexible system. (http://lemonstand.com/ http://lemonstand.com/)