I too use my Kindles to accumulate a library of reading material. So my TBR list is probably ready for a hardcover edition.
I probably have close to 500 titles across my 3 Kindles. It's fun to pick a random page from the home page and select a book to read I've totally forgotten I have.
I plan to be buried with my Kindle and a drop cord for power & light - so I can finish all of them.