This House M.D. fan art contains
boater, leghorn, panama, panama hat, sailor, skimmer, straw hat, fedora, felt hat, homburg, stetson, trilby, and sombrero.
There might also be
beaver, castor, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, pith hat, pith helmet, sun helmet, topee, and topi.