I prefer firm mattresses. I would say that the memory foam mattress I have is exactly what I expect from a "firm" mattress.

I didn't do a whole lot of research on the subject, but it does seem to be more common for memory foam products to be labeled as firm rather than soft. I bought a memory foam pillow recently, and it's pretty damn firm. Definitely the firmest pillow I've ever encountered. I wasn't happy sleeping on it the first couple of nights, but my neck is feeling noticeably better in the mornings. I'm going to try to adjust to the firmness.