I prefer Catholicism to other traditions for several reasons, the top reasons being the universality of the church, rich history of traditions and scholarship and a deep understanding of living the faith.
Of course Catholicism (little 'c') means universal. I can go anywhere in the world, even Saudi Arabia and find a Catholic church... that surprised me the first time I went there. So there is a large network of people that I can look upon as family. In addition, the communion of saints allows me to understand that the dead are just as connected to everything as the living and are still part of my spiritual family.
The scholarship of the church has led to the scriptures as we know them and has also led to what I consider the Catholic Church's biggest asset: An understanding that to live a life in the faith of Christ is to live with the scripture, with tradition (scholarship, practices, wisdom of others) and personal wisdom (the ability of each person to discern for themselves right v. wrong and the gravity of sins with a well informed conscience).
It only stands to reason that interpretation must be used in a book that was written 2000 years ago in different languages! By living only by the word of scripture can and has misguided so many.
John 8:32
And you shall know the truth, and the truth shall make you free.
john 6:69 And Simon Peter answered him: Lord, to whom shall we go? thou hast the words of eternal life. 70 And we have believed and have known, that thou art the Christ, the Son of God.
Well my parents were Catholic and I was baptized as an infant and raised in the Catholic faith going to Mass every Sunday so to start with I didn't choose to start being a Catholic. Later in life in my young adult hood I did explore other religions and other denominations. For several years I really didn't want to be Catholic and I protested against several of the things that the Catholic Church teaches.
I never really totally left Catholicism but I was pretty much trying to. I didn't make one clear immediate decision to stay Catholic but over a series of events it came to happen.
First, in spite of myself I found old churches and the Masses said by a few mostly elderly priests (this was late 80s) to be very beautiful and reverent and something in that pulled at my heart. It was just glorious and beautiful churches. In one case it was a very small college chapel but a mass said by a 90 year old Jesuit. I'm not sure exactly what it was, but something in a dozen or so of these experiences kept drawing me into the Church and the Mass. When I attended Episcopalian and Lutheran and non-liturgical services I never sensed any of this depth. For a long time I just considered that a product of my conditioning and being used to and comfortable in Catholic Mass. Now I think it is the presence of the Angels and Saints during the Liturgy around the true presence of Christ.
Second was reading books. I discovered Dorothy Day, Peter Marin, Thomas Merton, Jaques Maritin, "The Cloud of Unknowing," St. John of the Cross and many more and began to see that Catholicism was MUCH MUCH bigger than my suburban Church. I began to find the fullness of Catholic teaching. Later I read "Catholicism and Fundamentalism" by Karl Keating and began to understand the sources of the miss communications and accusations with evangelical Christians.
Third was beginning to Study the Bible and the Church. When I seriously began to read and study the Bible for myself on a regular basis I began to fully understand how the Catholic Church is the Church of the Bible. I had read the Bible through as a youth, but it wasn't until I dug into it for myself as an adult that I began to get over being intimidated by people who tossed off a few bible verses at me and made claims that confused me. There is not substitute for reading the verses in context and having enough familiarity to with the individual books (especially Paul's Epistles) and the Bible as a whole to be able to spot proof testing.
Also reading what the Church teaches from the actual source was a huge part of my choosing to stay Catholic. I argued about "Humanae Vitae" in particular and had real problems with the Church teaching. THEN I ACTUALLY READ the DOCUMENT!!!! Again there is to substitute for actually reading the source. I am still a bit angry 20 years later at how various people manipulated me by out of context quoting and distortion of the facts. The "Catechism of the Catholic Church" came out in English and I began reading and studying that along with the bible. Also with the Internet it became easy to get texts of all the encyclicals and other resources. So much easier today than when I lived in a small town in a rural area and there was no Catholic book store.
So now to answer a different question - slightly. Why do I LOVE being Catholic?
1) Because the Catholic Church is the Church founded by Jesus Christ on the rock of Peter and still here today through direct apostolic succession from Peter and the Apostles.
2) Because of the real presence of Jesus Christ physically in the Eucharist
3) Because Jesus Christ is the Head of the Church and the Church visible and united is His body on Earth with Pope Benedict the XVI has Christ's Vicar.
4) Because the Catholic Church is the Church of the Bible. If it wasn't for the Bishops of the Catholic Church up to and at the council of Nicaea we wouldn't have the Bible as we know it.
5) Because of Authority. Only in Catholicism is there a clear CENTER that this is the truth, the deposit of faith. In every other Christian 'denomination' I would always have to decide which preacher or theologian to follow or mix and match my own brand of Christianity (small c deliberately).
Well I could go on much longer, but those are the heaviest hitters.
G.K. Chesterton "Why I am Catholic" http://chesterton.org/gkc/theologian/whycatholic.htm