Caliban has a great selection of interesting and diverse books. It's organized in a good way and even though it's not all that big, I've found that I can get lost in a section while perusing what's there. Within each section, there's a lot of diversity.
Upstairs has almost all hardbacks, and the smaller downstairs is just paperback books. One of my favorite parts of Caliban is their record section. Tucked into a corner, their record section has been growing over the last 6 months or so. There are a number of record stores in the city, but every once in a while I find something at Caliban (actually the record section is called Desolation Records) that I can't find elsewhere. They started selling a few used records as well, and you can find a few gems there too.
If you like books, or records check it out.