I'm reading Dante's Divine Comedy right now. I only read a couple chapters a day but it's very satisfying even in small bits.
>What is the merits to Christian art when both the scriptures and the writings of the saints exist?
You get to meet new characters and see the truth from different angles. We can learn from great thinkers whether they are Protestant, Catholic or Orthodox and even the Stoics/Platonists have a lot of wisdom.
>Any personal favorites?
Arvo Pärt's music.
Andrew Murray's books "Abiding in Christ" and "On Humility" are really helpful for spiritual praxis, purity of heart and growing your faith into something resilient.
Seneca's letters, "On the shortness of life", Seneca was seen as an honorary christian by some early christians, like Tertullian, Jerome and St.Augustine.