I've been cataloging the books I own on a spreadsheet on my computer since 1985.  I've taken that original list through many changes of format, many changes of program used to edit and many different computers.  I love that list and I've protected and backed it up in every way I know since I've spent untold hours getting it the way I want it.  One thing I never did on it though was put ISBN numbers.  They never mattered to me for my own private books.  Now, I would like to get my books cataloged online but I can't just upload that list since it has no ISBNs for over 3000 books.  So here's my question.


If I'm going to take the time to enter all those again at a book cataloging site, which one should I put my time and effort into?  I'd love to enter them here but the book catalog isn't quite what I need yet.  I would love to find the one site that does book cataloging perfectly and then export it to the other sites I use.  I know, no one site does it perfectly but I've looked at Goodreads, Librarything, Leafmarks and libib.  Strictly looking at cataloging, no social features, which one is worth putting my time into to reconstruct my library online?  Or is there another one that has even better cataloguing features?


I'd sure love to eventually have everything right here on booklikes.  Any thoughts?