Other than the usual trilogies, The Hitchhikers Guide to the Galaxy. My longest series was The Dark Tower by Stephen King though.

The Neverending Story. Whoever thought it would be a good idea to take a dragon and turn it into a flying puppy should be banned from filmmaking for life. Not to mention all the other ways that this abomination twisted a great book into a complete mess.

Barack Obama’s autobiography. I have nothing against the guy but I just don’t read autobiographies, let alone 1000 page autobiographies.

Making History by Stephen Fry. Absolutely great and would make an awesome miniseries, too.