So many great masters of photography created amazing images when black & white was the only option. Black & white images can highlight textures and patterns of light that color can often distract from.
Capturing light playing or subjects moving in unique ways can create very interesting images. Often these sights cannot even be seen by the naked eye such as foam swirling beneath a waterfall.
Night photography provides many more opportunities for photography than one might think. The images that can be created after the sun goes down can be very interesting and unique.
Panoramas interest me because they can often reflect what a traditional sized photograph cannot such as the grandeur of a range of mountains stretching across the horizon or the immensity of the Niagara Falls from below.