World view issues and ethics are hard subjects to address. The best books that deal with these as far as I can tell are from the Middle Ages. That is there is a set of books from the Middle Ages that deal with world view issues. Mainly that is Saadia Gaon, Maimonides, Crescas, Joseph Albo, and Abravenal. There are also books that deal with ethics. That started with the Obligations of the Heart (Chovot Levavot). After that there were a few more. Shaari Teshuva by Rabbainu Yona, Orchot Tzadikim, and a few others. These all seem to me to be the best.
After the Middle Ages logical thinking in these subjects went out the window. People that were good at logic then went into math and physics and the natural sciences.
So while the natural sciences benefited, ethics and world view issues suffered.
So while it is admirable the attempt of Avigdor Miller to defend Torah, still his books are not good arguments. If you want to defend Torah you really have to go to the Middle Ages when people were thinking clearly in these matters.
With due respect, Rav Miller did not understand evolution. Genesis and the Big Bang is full of errors in both Torah and Physics. [But in terms of presenting the idea that Torah and Physics are complementary it is an inspiring book. He gets a A for effort.] No book that has been written in the frum world about ethics or world view rises above comic book level. The mystics are even worse.
Not one of them has the slightest idea of what the Ari was talking about.
So while defending Torah is a noble and worthwhile task, it does not help the cause to have idiots and schizos doing the work. They damage the cause by means of their support. And they change the Torah to fit their delusions.
However I should mention the Chafetz Chaim and the Musar books of the disciples of Israel Salanter are excellent.
Shimshon Refael Hisrch is excellent and so are Rav Cook's books.