This Nathan Fillion & Stana Katic photo contains
fedora, felt hat, homburg, stetson, trilby, boater, leghorn, panama, panama hat, sailor, skimmer, straw hat, porkpie, and porkpie hat.
There might also be
beaver, castor, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, well dressed person, suit, pants suit, and pantsuit.