The most "miraculous" one involved my brother. My dad and my brother flew out to St. Louis for my son's Confirmation. My brother was his sponsor, and my mother wanted my dad to go with him because he had been diagnosed with MS the year before. In the months since I'd seen my brother, his condition had deteriorated quite a bit. He had a pronounced limp, and when he tried to pour milk into the cereal bowl his hand shook so that he needed help. I found myself on the verge of tears (which I tried to conceal) much of the time.
I was singing with the choir during the Confirmation Mass, and as I saw my brother limping up the aisle with my son as he was confirmed, I couldn't shake my sadness. When we all held hands to say the "Our Father," I felt the Holy Spirit's presence so strongly, and I prayed that my brother would be healed by his presence at this Mass. We were singing the Communion hymn as he limped up with my son to Communion and right as they walked by the choir he straightened up and began walking perfectly. He went into a remission that lasted several years.
This happened over twenty years ago. His MS has progressed, although he is still able to walk. He has some vision problems. He is retired.
But I firmly believe that the gift of that several-year remission was a miracle, granted after my heartfelt prayer.
There have been other 'miracles' I've experienced and family members have experienced, but never one with the instantaneous connection as my brother's remission. I've got to go to work soon, but maybe I'll post a few later.