Romance novels. Modern romance novels. You know the type. There's always a bare-chested man with superhero dimensions and long, flowing hair with a woman who through artifice or accident has managed to demonstrate a remarkable amount of cleavage and expose at least one shapely leg from toe to 3/4 of the way up her thigh. She will either be clinging to him as to a life ring in the stormy Atlantic while they gaze intensely into each other's eyes or busily swooning whilst he effortlessly supports her with one arm and stares broodingly into the middle distance.
Also, no modern crime whether true or fictional. I don't need to read vicariously sadistic accounts of gruesome murders.
There are lots of other books I won't read or am not interested in reading, but no other genres spring to mind.