I write fantasy and have recently started experimenting with erotica and erotic romance. Together those genres are definitely a lot of what I read, but I love SF (as long as it isn't preceded by the word 'hard' or 'military'), horror, GLBT fiction, dark contemporary fiction, literary fiction, and experimental fiction (as long as it doesn't break my brain). I want to read some more gothic or paranormal mysteries but am having trouble finding good ones. I will occasionally read a YA book if it looks dark and interesting enough.
Definitely the variety of fiction I read has helped my writing. All the erotic romance reading makes my romance subplots very strong and my interest in literary fiction helps me emphasize character and theme. My long background in horror shows clearly when I write action and adventure scenes (they tend to be less pleasant and more visceral than is typical for epic fantasy). Every genre has overall strengths and weaknesses, so you can learn a great deal by reading widely.
Actually, I think I may have chosen epic fantasy as my genre not because I like reading it best (though I do enjoy it) but because it allows me to incorporate elements of all other genres. I like taking the strong, complex plots natural to epic fantasy and adding heavy amounts of eroticism, horror, and deep character exploration. Of course, this requires me to be good at everything . . . lol