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