I don't have a 'to be read' pile in the sense of a pile of unread books. I shelve them when I buy them so there's several hundred unread books scattered on shelves all over my home.
Next to my bed I have a small pile (usually five or six) books that are currently being read. When the pile runs down and all the books have been returned to the shelves I walk around and pick out books to rebuild the pile.
It very much depends on the mood at that time. They might all end up being non-fiction, or collections of stories for example.
Right this minute there is Mister Pip by Lloyd Jones, The History of Mr Polly by HG Wells, Dark Alchemy edited by Jack Dann & Gardner Dozois, Love In A Cold Climae & Other Novels by Nancy Mitford and I Am A Cat by Soseki Natsume.