The majority of my reading is outside the genre that I am currently writing. Most of the time I write in the "literary" genre (I don't think literary is really a genre, but that's another debate), but spend more time reading Sci-fi, Fantasy and non-fiction.

However, I don't believe genre is something you should make an active choice to write in as an author. The genre is dictated by the story you are telling. So, really there is no reading "outside the genre you write" but rather, "reading outside the genre you are currently writing."