Don't forget about "Brat" bikes!
I have always heard that a "streetfighter" is a sport bike with the fairings removed and a couple of inches of extra rise on the handlebars. I think "bobber" is a bit more difficult to define since it is can be an amalgam of various "bob jobs", including aesthetic and performance upgrades, but my impression is they are kind of between cafe bikes and choppers in terms of modifying to look unique versus making potentially legitimate performance upgrades.
Anyway, that's my two cents. I work in the bicycle industry and notice lots of funny trends, especially towards retro styles, like the "constructeur", "randonneur", and "porteur" styles that are popular with custom frame-builders lately, for instance.