It used to be a todo list set up where I just check off and add whatever books caught my interest but it wasn't very shareable so I moved onto storygraph which I liked more than goodreads as the data visualization and breakdown of books via tags and moods gives me a better idea of where I tend to lean in books I seek out and which genres I rarely touch at all.
I'm also a Storygraph person for tracking my reading! My to-read list is a text file though.