This Doctor Who screencap contains
filzhut, homburg, stetson, trilby, fedora, and stetson trilby.
There might also be
boater, leghorn, panama, panamahut, seemann, skimmer, hut stroh, bootsfahrer, bein, strohhut, livorno, panama-hut, porkpie, porkpie hut, kampagne hut, and kampagnenhut.
Basically the story of his three companions, Rose, Martha, and Donna, and how they can never stay with him long, and the Doctor has to let them go. Made Von zcatz.