I mostly listen to metal however I have recently widened my horizons to include various other genres.

My favorite, something with heavy guitaring along with symphonic elements and operatic female vocals. This can range from "Evanescence" to "Therion". I also think the category is easily complimented by techno elements like “Theatres Des Vampires”.
Another type I enjoy is something with loud and violent guitaring and equally as loud and violent male vocals such as "Farmer Boys". I also like this to sometimes include industrial elements much like "Deathstars".

I also like stuff that has light electric guitaring, or usually acoustic guitaring, however the dominant instrument would usually be keyboards. Vocals in this category are typically somewhat metallic. A good example of this would be " Ladytron" or “She Wants Revenge”.
I also have an appreciation of classic rock. This is my widest category, ranging from “The Rolling Stones” to “Queen” to "Blue Oyster Cult".

Oh, and I would also like to add that rap is nothing more then a plague to this planet.