(1)
$ curl http://alexott.net/en/fp/books/ 2>/dev/null | \
grep -o 'http://www.amazon.com/gp/product/[a-zA-Z0-9]*' | \
sort -u | wc -l
132
Seriously, you've read 132 technical books, for 10 different languages, going back to 2009?
(2) I'm seeing books that have been OK-ish when they appeared and thus recommended by people, either because of lack of other choices, but also because the advice contained was the status quo, but right now are pretty bad choices. "Programming Scala", by Alex Payne, for example is an awful reference to put on any list of books for Scala. It contains bad practices, plus lots of references to obsolete parts of the standard library, not to mention its general flow is just awful. If you would have read it, you would have known. "Programming Scala" the one published by the Pragmatic Programmers, is another awful choice. Actually, all books on Scala published before 2010 are awful choices.
(3) What the hell does a book on Scalatra has to do with Functional Programming? Is it because the association with Scala or something?
(4) It's bad advice to tell people to buy books from Amazon. The E-Books are DRM-enabled Kindle versions, sometimes badly formated and you don't get the PDF. Many of those books have the same price if you buy straight from their publishers and you get both a DRM-free Kindle version and the PDF.