I think the best ones are where you talk about an interesting story or real-life example that somehow gives an idea of what you are like. If you are EMS, sure you can talk about doing CPR on someone although honestly that is kind of boring. I would much rather read about a unique experience that is either funny, or shattered an world view you had, or is just somehow unique. Like did you ever get a 911 call to a treehouse. Or ever show up to a mine and the caller is down in the mine shaft 200 ft below the ground, or you showed up to someone who had a metal rod going through is brain, yet was awake and talking. Shiit like that.
Don't write about how you love ER because of X, Y, etc. And you are special. I never officially reviewed personal statements for admissions committees, but I used to hire people when I was a manager in Tech, and the best CV's and personal statements were ones that either made me want to read more....or said something like "I can help your company do A, B, and C" and those things are very specific and something that I need.