given the number of times I've re-read or started re-reading a book, perhaps I should do this. Same with the occasional movie....
I started using Goodreads, but found I didn't look at it. It's like tracking beer or wine I like, I just wing it.
I had the same exact issue. I really had to commit to using Goodreads.
I recently added a couple of new shelves into my goodreads that help me track my "Want to Read" books. The shelves are a) already own the book; b) can get the book at the library c) have to buy it (hopefully used or on sale) d) not yet released
Other categories I have are:
Hugo nominees and winners
Nebula nominees and winners
World Fantasy nominees and winners
RPGs (of course)
Non-Fiction (which someday i may further break down)
Goodreads doesn't give me a good way to figure out which books are NOT assigned a certain shelf; or which books have no shelf at all...
Anyway, Goodreads allowing me to sort my books I want to buy means it's really useful now