A homburg would be the classic option. You could get away with a black fedora in most circumstances. Of course, if you're choosing to wear a hat with black tie these days, it seems that a homburg would be the way to go. The most affordable quality option would be by Akubra.
During summer months, you might choose a Panama with a black ribbon.
Crittenden Clothing was founded by Oxxford president Critt Rawlings following his retirement from Oxxford. Rawlings has worked at Oxxford, Ralph Lauren and Norman Hilton. He knows clothes. His approach for Crittenden was to take his knowledge of high-end tailoring and apply that to off-shore production. His focus has been on more relaxed, unstructured jackets suitable for casual and business casual wear.
You can see the quality of Crittenden explained with this...