I have a "collection" in my bullet journal for it, but I don't maintain it too much. Occasionally when I'm done in a book I take a glance at it and see if something strikes my fancy but I also quite often just pick something up on a whim. I won't fret if the list is lost either.

I use the wish list option in my library's online app. I get all my books there now. It is the only way I can read a book without procrastinating. In the past I would buy books and they would stay in my bookshelf for ever. That mostly stopped since I have a limit on how long I can keep the book before I have to return it.

My-simple-stack-system, current to next; on my writing desk's right(ish?) areas and old Kobo taking up some space here too > second shelf of the nearest (to my writing desk) bookcase > bookstores (physical or online), libraries (private, proprietary or public), online sources, etc.

I have a somewhat literary knowledge base of text (.txt) files on a Git repository, e.g., to-read.txt: Author, Title (ISBN). I've tried some independent literary platforms (re: https://oku.club/) but they fall short in terms of being ISBN-specific.

In a text file that I cull every so often. Not that the culling works – I tend to add a book for every one or two that I remove from the list.

I maintain my to-read books list in Notion. I've seen the positive impact during the pandemic mostly.

In its own Todoist list.