If you're struggling with sin, if temptations are half-killing you, if all seems lost - maybe have a word with one of the following in prayer, and ask for a little help. After all, as my parish priest always reminds me, we are a community.
1. St. Margaret of Cortona
Formerly a mistress and rather loose woman, St. Margaret is now known as being a humble penitent of the Third Order of St. Francis. She struggled with all kinds of sexual sin and temptation during her life, but turned that strife into a newfound love for the poor. If you are the kind of person who struggles in a similar way, perhaps a quick prayer to St. Margeret might be in order?
2. St. Anthony the Great
The temptations endured by arguably the greatest of the Desert Fathers are the stuff of legend. My admiration for this man was once even declared to be almost pagan by a friend of mine, because I had made him out to be almost heroic in the Greek sense. My own follies aside, I have always considered St. Anthony the Great to be the patron saint of those who struggle with sin and temptation of any and all kinds on a heavier than usual level - indeed, a simple reading of his Vita by none other than St. Athanasius is enough to inspire a Christian for a lifetime.
I think that there are few saints in the Catholic world that could ever be of more benefit to a Christian reader's soul than St. Faustina. A simple picking up and reading of even a few lines from her famous Diary is often enough to dispel the darkness of despair over sin and feeling unworthy of the mercy of God.
4. St. John Vianney
In many ways the model priest, St. John Vianney inflicted penances on himself for the sake of his flock, waged a prayerful war against the demonic nightly, and would spend almost entire days simply hearing the confessions of sinners. He is, in many respects, the ultimate choice for a patron when one needs a good and holy man to pray on their behalf.
5. St. Catherine of Siena
What inspired me most about this wonderful saint and Doctor of the Church was a story about her visits with a young man convicted of a serious crime and sentenced to die. From what I remember of the tale, she did not leave the young man's side until she had awakened within him a perfectly contrite heart, and won his soul over to Christ. She went with him to his beheading, encouraging him the entire way, and assuring him of the heaven that he was about to enter. According to her letter concerning the event, she even held his head in her hands as it was severed from his body, and witnessed his soul ascend to glory. She was with him to the end, and this to me speaks of a true patron for us sinners.
The Confessions. That is all.
7. St. Catherine of Genoa
The saint who violently experienced Purgatory and the sufferings there, St. Catherine, once indifferent and prone to depression, as well as being unhappily married, became on of the greatest mystical saints of all time. She devoted her life to caring for the sick and poor, had mystical experiences that were so famous that they became central to a study by William James in his The Varieties of Religious Experience, and became a patron of those suffering from sinful temptations.
This pick probably comes a bit out of left-field, given that I think few Catholics in the West really know of this exceedingly holy and richly-spiritual monk. His writings focus on the need for the gift of tears and repentance, and yet emphasize so very strongly the love and mercy of God that few have been able to touch it since. His homilies and writings will comfort any soul afflicted with sin.
9. St. Patrick of Ireland
It might seem off to pick St. Patrick for this list, but if one reads his not-famous-enough writing, the Confession, one will see why I did. He calls himself the worst of the worst, unworthy, a coward, and a borderline imbecile, and yet he was still called by God to serve Him by almost single-handedly converting an entire country to the faith of Christ. He struggled vehemently with all kinds of temptation, doubt, and hardship, and yet pulled through. And though today, St. Patrick's Day has become little more than a bro-show for those who probably don't even have the slightest clue about the most beautiful country in the world, nor who its most beloved saint actually was, some of us penitent Catholics out there especially raise a goodly pint in honor of this wonderful saint on that day. A most inspiring figure, even for the most hardened sinners among us.
The Refuge of Sinners - the one whom it was never known that a sinner, no matter how wretched was turned away from. Yes, it's our Savior's Mother. And sometimes, when the going gets rough, and we become bogged down in all kinds of hell and sin and depravity, not only is Jesus there to pick us up, but if we are to afraid to ask Him, sweet Mary will lead us to Him by the hand and help us back up to our feet again through her prayers.