This Professor Mcgonagall photo contains
fedora, felt hat, homburg, stetson, and trilby.
There might also be
boater, leghorn, panama, panama hat, sailor, skimmer, straw hat, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, and beaver.
SPOILER for whose who hasn't read Half-blood Prince yet: after Dumbledore's death, Minerva tries to recall her memories about their hidden love and decision of breaking up.