The scariest thing that ever happened to me was my dad's cousin coming to our house one night high on speed. I had to call the cops on him because he was telling my mom that people were coming to kill us. I took all my siblings into my brothers room, locked the door, and I called 911 while they all sat together. It was actually quite terrifying. He didn't have a gun, but he kept asking to get my dad's out of the closet because of the 'people that were coming to kill us'. He was crawling around on the living room floor, ducking behind furniture. He kept telling my mom to get down, too, that he could hear people saying they were coming. It was infinitely creepy.
The second scariest thing was when me (15 at the time) and my sister (13 at the time) were walking our trash cans down to the bin. We didn't live in the suburbs, we lived in the middle of no where. Our trash bin was about a quarter mile away from our house, down one longer stretch of road, and then around the corner down another shorter stretch. Unfortunately, all of our neighbors were redneck scum. Well, as we got to the end of the first road, there was a house on the left side. An old guy lived there, we knew him more or less because he would come down to our house asking for money or whatever. He was an alcoholic, no doubt about it; His friends that lived in the house next to him have been arrested before for cocaine, and prostitution. Not to mention we heard him IN BROAD DAYLIGHT selling weed to this guy who didn't even live in the neighborhood. (I'm not anti-weed; It's just that weed is illegal here.)
ANYWAYS -- as my sister and I got to the end of the road, like I said, his house was right there. Him and some other old guy pal of his were drunk off their rockers (mind you, it was around 1pm) and sitting on the front porch. They started whistling and catcalling at me and my sister. Let me remind you: I was FIFTEEN. My sister was THIRTEEN. I was so ****ing terrified I told my sister "We're turning around. Now."
We walked all the way back up to our house and at first my mom was angry cause we still had the trash cans, but then she saw I was bawling and I told her what happened and she was so angry at them. She called my grandpa, who lived right up the road from us, and he came over to their house and called them out on it. He was disgusted. It didn't turn out too well because they were drunk, so as my grandpa made his way back to our house we started hearing them yelling. "I'm gonna burn your ****ing house down!" they kept saying. It was so scary, dude. My grandpa had my mom get behind one of the vehicles while we waited for the police to arrive just in case they started firing.
Anyways, after that we were so terrified that we actually stayed at a hotel for about a week until my dad got home. (He works overseas and all the bad stuff seems to happen when hes gone.)
Later I was actually subpoenaed to court as a victim/witness/whatever but luckily the trial never actually happened because I was way too young and way too scared to know how to handle that; ESPECIALLY since those dumbass guys kept denying what happened.