This Matthew Gray Gubler photo contains
fedora, felt hat, homburg, stetson, trilby, well dressed person, suit, pants suit, pantsuit, boater, leghorn, panama, panama hat, sailor, skimmer, and straw hat.
There might also be
dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, outerwear, overclothes, beaver, and castor.