I don't keep a formal list of what I want to read in a particular place. I have a notebook that I jot down notes and ideas in when I am reading, and occasionally books I am interested in reading will be written down there as well. This helps me remember book recommendations or books mentioned in other books. If I have access to my computer when I get a book recommendation, it might go on a library list.
I have books that I want to read that are not written anywhere. Some of them are classics that I haven't had the opportunity to get to yet. One book I have on my unwritten list is Wuthering Heights. I have tried to read this book on three separate occasions, and I even know the general plot and characters. I haven't made it through the book. However, I have a number of friends that really enjoy it, and I would like to read it for this reason.
This list has also manifested itself in physical form. There are books in my house that I haven't read yet. I purchased them or received them as gifts, but they languish on the shelf. Why do I keep putting books on hold at the library, if I have unread books at home? This question has a complicated answer. (Which I may delve into in a future post, but not today.)
I have attempted to write out a to-be-read list in the past, but the pace of my reading quickly outdistanced the list. It was frustrating, and I felt constrained to read a specific book at a specific time. The lack of system is working pretty well for me right now.