I'm from a country in Europe, so prom would be a bit different, more modest I guess. Some people arrived in limos and had fancy dresses anddates, but most people didn't follow the rules too much.
I went when I was 18 I guess and it was good fun. I didn't have a date, just went with friends. We went for dinner beforehand and then we went to prom and danced a lot. I don't recall drinking a lot or losing my virginity (like they seem to do in America), so I guess it was a great prom. Totally fun. Wore a somewhat fancy dress. Drank a drink or two and came home by 2. Haha.