What are some books you just must have on your bookshelf as a philosopher?
If you’re a beginer looking to just get into philosophy Peter Kreeft’s The Journey is a must have. Be warned: 2/3 of the way it turns into theology.
For those of you looking into getting into theology and the bible (Quor’an, whatever) isn’t enough, I say: “Good for You!” The bible isn’t enough for me either. If you are looking at a Judeo-Christian picture of theology the must have it the Summa Theologica or the Summa of the Summa, but everyone expected me to say that already, didn’t you? 
To understand Catholicism the Catechism by Pope John Paul II (Vatican II edition) is the book containing the official beliefs of the Catholic Church. A Must have. I recomend reading it in conjunction with St. Thomas and St. Augustine.
For moral reletivists I recomend Kant’s The Metaphysics of Morals.
For everyone I recomend Aristotle for Everybody.
Happy reading!! I look forward to your recomendations.
P.S. This will probably determine what books I read next (maybe even put on my Christmass list) so I’d appreciate as much input at possible. 