I have become a collector of various books which support my religious life. I think there are a number of books one needs in order to be a functioning, practicing Catholic -- yet for many years I neglected building my Catholic library. In the last year, though, I've gotten a pretty good collection going. I now have five different editions of the Bible (including a copy of the Vulgate), the Liturgy of the Hours in both Latin and English, the Catechism, the Raccolta, the modern book of rites, a Latin-English Rituale Romanum, and two daily missals (one for the Extraordinary Form (Tridentine mass) and one for the Ordinary Form. I have numerous other works on apologetics, and a fairly big bookshelf on the topic of demonology. I got interested in the sacramental of exorcism mainly because in re-reading the New Testament for the first time in many years, I was struck by how many exorcisms are in it, and wanted to research the church's current view of it. (I've completed that research to my satisfaction; and although I'll certainly want a copy of Fr. Fortea's Summa Daemonica when it become available in English, I'm no longer that interested in the subject -- my conclusion being it's very real, it's thankfully rare, and should be left in the hands of professionals).
But the book I use most frequently, besides the Liturgy of the Hours, is the Daily Missal. In that I only attend the Extraordinary form of the mass occasionally (three or four times a year), I usually use this book most Sundays, and when I go to mass during the week, I am also prepared with all of the readings ahead of time. Now certainly, the church provides missalettes, so you might ask, "Why do I need a missal at all?" My answer is that a hand missal usually has in it a lot more than simply the readings. It also has a short form of the catechism, and devotional prayers that are helpful in preparing for mass. This particular edition of the Daily Missal has the readings for years A, B, and C of the modern lectionary cycle all on the particular day, and it is therefore easy to follow. It is a good edition, though with as much Scripture as is in the modern mass, it is a little bulky. This version is of good quality, with beautiful old woodcut illustrations. The downside is that is also a tad pricey at $75.
I got mine at Aquinas Books.
What I like about this edition is that it has an excellent collection of prayers, and has many of them in both Latin and English. There are four particular prayers in it that I now read before/during/after mass -- the prayers of St. Ambrose and St. Thomas Aquinas before communion, and the prayers of St. Bonaventure and St. Thomas Aquinas after communion, as part of my thanksgiving. Aquinas's prayers, in particular, are always well written, on point, and instructional. Although he is best known as a theologian, you can definitely see the clarity of his thinking in his prayers and his hymns, which are, to my mind, great treasures of the church that must be recovered. I do not have time right now to reproduce them in Latin and English, but I will at some point. Here is a page that has versions of both prayers, though the translation I have from this missal is slightly different.
And in Googling for them, I found this little book, which I'll buy soon for my bookshelf.