It might be better now than since I last looked, but the one language I haven't found a good tutorial for is Haskell.
All the ones I've seen either dumb things down way too much with cartoons and such until they're difficult to slog through and pick out the relevant info, or they assume the reader either already has a working knowledge of Haskell syntax or a working knowledge of group theory.
I found 'Learn you a Haskell for great good' (http://learnyouahaskell.com/) excellent. It does not depend on the cutesy cartoons and nothing is dumbed down. I think it does not suffer from the criticism levelled in this article: it has plenty of code in the introductory chapters. Not 20 lines, but that's because fewer lines are needed.
All the ones I've seen either dumb things down way too much with cartoons and such until they're difficult to slog through and pick out the relevant info, or they assume the reader either already has a working knowledge of Haskell syntax or a working knowledge of group theory.