This Jeremy Brett photo contains
fedora, felt hat, homburg, stetson, trilby, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, boater, leghorn, panama, panama hat, sailor, skimmer, and straw hat.
There might also be
campaign hat, snap brim hat, pith hat, pith helmet, sun helmet, topee, and topi.