I have a few:
St. Margaret Mary - I spent a good few months poring over her autobiography and various biographies and works on the Sacred Heart. She ignited my devotion to the Sacred Heart, and in return, I hold a devotion for her.
St. Bonaventure - I love his theological works and the more poetic way he writes.
St. Augustine - my patron Saint, my favorite theologian, and his own later conversion reminds me of my own in some ways.
St. Alphonsus Liguori - His sermons and "Preparation for Death" made me fall in love with his works.
St. John of the Cross - His works which incorporate the apophatic theology of St. Dionysius were honestly life-changing for me. I frequently return to them.
Pope St. Pius X - For obvious reasons concerning his stance against Modernism. But also his tremendously simple and humble demeanor as the highest living authority provides an incredible example for all Catholics.
Pope Innocent III - A Canon law expert who reigned during a time of tremendous Saints with great wisdom, I feel myself drawn to him.
Pope Pius IX - Again, for similar reasons on his stance against Modernism, as well as his work to define papal infallibility during turmoil in Italy proved his resilience and fortitude. Plus, he is a prime example of the effect of the grace of office associated with the papacy.