My favorite genre is metal. I like the rough sound of it, as well as the ability of metal to get pretty melodic, depending on the sub-genre. Speaking of which, I like how diverse metal is; although I don't like every form of it, I like how there are different kinds of metal. If you want something fast and melodic, there's power metal. If you want something fast and in-your-face, there's thrash metal or grindcore. If you want something heavy and melodic at the same time, there's melodic death metal or melodic metalcore. You want something plain heavy, there's death metal or black metal. If you want something with good riffs, there's classic metal, progressive metal, or glam metal.
Aside from bands that have violent, materialistic, or satanic lyrics, I like how metal lyrics are often serious in nature, and appear to have been well thought out. Metal covers a wide variety of topics, depending on the sub-genre or band. Along with the lyrics, I enjoy the composition; to me, metal has the best musicians. I especially enjoy songs with guitar solos, and drummers who do double bass, blast beats, or gravity rolls. Sometimes, the bass player is good (Iron Maiden and Necrophagist are good examples, though the latter is a death metal band, one of the few that I like). The rhythm guitar in metal often has nice riffs. The vocals can vary, which adds to the variety; if you don't like death metal because of the growling, for example, you can listen classic metal, which has singing. In conclusion, I enjoy metal for its heaviness, diversity, and composition.