I terms of Torah what I suggest is the books of Rav Shach and Reb Chaim Soloveitchik. And the basic Musar books I think you should know. There is a set of the classical Musar books the are the Chovot Levavot, אורחות צדיקים ספר הישר של רבינו תם. There are also a few books from the direct disciples of Reb Israel Salanter. מדרגת האדם אור ישראל. That is Reb Israel had one disciple Joseph Horvitz from Navardok and Isaac Blasser.
Not everything the people say that sounds like Musar should be accepted as Musar.
You see Musar itself is based on certain world views that the rishonim had. So even if you do not see them discussing their world views in their Musar books, still there is a strong connection between their world view and the Musar they wrote. So learning only the Musar means often people pick up world views from other sources without knowing it. So I see learning the Emunot VeDeot of Saadia Gaon and the Guide of the Rambam as being very important.