So why are you asking?
I know you do, and I don't blame you. Spiritual experiences of any kind are very personal and very subjective.
I couldn't possibly even begin to give you even a sampling of the kinds of things I've prayed for in the past five decades. To begin with, it would take a lot of my time and you would completely disregard everything I said anyway. Seriously, if you were me, would you bother?
I will tell you the first time I was convinced that God had actually answered one of my prayers. I was maybe three or four years old. One day I was playing with what my mom used to call "the bell." It was one of those little portable timers people use when they're cooking (nowadays they're generally built-in, but this was a long time ago, and ours wasn't). Anway, I was sitting and winding it just past the 5-minute mark and then immediately backwards to where it would go, "ding!" So it was wind clockwise, wind counter-clockwise, ding! Wind clockwise, wind counter-clockwise, ding! Over and over and over again. Finally my mother said to me, "Kathryn, don't do that any more. You're going to end up breaking it. It's not supposed to be a toy." Well, since I was so much smarter than she was, I just answered, "No I'm not! See!" and I continued to go through my little routine. A bunch more winds, a bunch more dings and all of a sudden, the bell stopped working. Guility, I handed it to my mother. "Im sorry," I said. She tried for a few minutes to get it to work. Finally, she said, "Well, I told you that's what would happen, but you didn't listen to me, did you? We'll just have to buy a new one."
"No we won't!" I said. "I'll pray about it. I'll ask Heavenly Father to make it work again." My mother really didn't know what to do. She'd taught me to pray and to have faith that God would hear and answer my prayers, but she knew that He didn't waste His time fixing mechanical timers. She hesitated and started to try to discourage me, but I was insistent. "I'm going to pray!" I said. And I did. After I asked God to please fix the bell, I went over and picked it up. I wound it just past the 5-minute mark and then backwards. DING! What a beautiful sound! I handed "the bell" to my mother, who was standing there were her mouth open. My mother is 95 years old. She still remembers that incident. I do believe God answered my prayer. I also doubt very seriously that I would have enough faith to make it happen again today, but I bet a lot of children would. I believe God knew how important it was that He answer that prayer. He knew it would influence the way I thought of him forever. He gave me what I needed then. What I needed from Him then and what I need from Him now are very different, but He still responds and placebo effect or not, when I still see the results of my prayers, I am going to keep praying, regardless of how stupid, naive, or humorous people like you may find the practice.
I'm sure I did make a choice, but it was definitely even further back than the one incident I recall so clearly. I have seriously tried to convince myself that it's all just my imagination and that there really is no God. No matter how hard I try, I just can't make it happen. I'm sure it's not genetic, but it's something that is as much a part of who I am as the color of my hair and eyes. And believe me, I could change any aspect of my physical appearance easier than I could change my feelings about the existance of God.