There are plenty of books that should have done better than they did, not only in terms of sales, but interest and longevity. Writers love trading recommendations on these sorts of things. The Irish Times looks at a bunch here, but I wonder what your recommendations would be. Books that should really still be getting attention, or should have on release, but are relegated to the remainder bin of history. I think Beautiful Losers by Cohen is one of these. Too profane for its time, but I’m surprised more young people aren’t reading it now. In general, there’s no way to really tell which books will stand the test of time (how many reviews for super popular authors have called their subjects “timeless” or “masterpieces” only to have the author disappear into relative obscurity two decades later. Hell, there are writers who were THE SHIT when I was first starting to write who aren’t, by appearances, around anymore. Neglect happens in real time, but it’s only from a distance that you can see exactly how much damage has been done. So, support the books you love and put them in the hands of others!