Hell, to me, doesn't really exist. Since I am Jewish, I do not believe that there is a hell because that is what my religion says. However, I do believe that torture exists, especially of the mental kind, and that any one person could suffer the same amount of pain as any level of hell simply by thinking too hard. So hell does sort of exist, but it is all internal. Within each of us, there is a hell. But as a whole, I don't really think there is anything.
To get into my hell, you don't have to be truly terrible. It's a bit like jail, except that nobody is capable of escaping the prosecution and it's not actually possible to weasel your way out of a sentence. Everything about your existence is basically projected up onto a big screen. Like, absolutely everything. All the good and all the bad. Then you are judged and sent to hell for a certain amount of time. Since nobody is perfect, everybody will go to hell, but the nearly perfect people will only be there for a short amount of time. I forget which mythology it is exactly, but in one of the Greek stories (I think) you can work off your time depending on how terrible you were, and your punishment depends on that. But in my hell, nobody gets off scot-free if you were bad at any point. I wish I could be more specific, but everyone has done something, therefore there are no specifics. Everyone who deserves a punishment gets it.
The punishments depend on the crime and, of course, the person. For everyone is would start by being humiliated and embarrassed by their entire lives played out on the giant screen in front of everyone else. But it would mostly be a highlight reel of all the worst things, and then everyone would laugh at you. The next thing would be utter isolation. Not just being put in a room, but basically being dropped into black hole. You won't know which way is up and which way is down, if you're ever going to land, where anything is in relation to you. Utter blackness and disorientation, like Tartarus. The Greeks had the right idea with that one. Then there's the real torture. Not pain necessarily, because people can get used to pain, even though that would still be up there. For me personally, it would be the sound of hundreds of keyboards typing away irregularly, and dozens of nails tapping a plastic table, the scratching and tapping of pencils writing away, and the sensation of fingernails bending backwards, feelings so awful they send shivers up your spine and layers upon layers of pure asymmetric noise with no way to block it out and no white noise to wash over it. For everyone, it would be facing their worst fear combined with their worst nightmare.
Hell's appearance would be as customized as the punishments. For some, it would be teetering on the edge of a railing, adrenaline surging as they almost fall again and again. For others, it would be creeping away from something they can never quite see but are sure is there. Maybe standing in line forever, inching forwards but never quite reaching the front. Or perhaps slowly crawling along in bumper to bumper traffic, or following a clump of slow-moving people that are impossible to move around. The reason why all of these are mobile is because you would only really get the chance to look around and appreciate (or curse) the interior decorating is between punishments. Almost like school, you would be punished for an amount of time that you know and can only hope to make it through (which would likely be somewhere in the dozens of years range for an average person) and then brave the hallways to get to your next class...or, um, punishment.
Everyone escapes eventually. Hell is just a cleansing process, and there are obviously no relapses. Who would want to face all that again? Almost as a reward for all the good things in your life, you spend your time in hell and then are rewarded by spending the rest of eternity in heaven. It's only fair, after all. And even the worst of people can change. I truly believe that. After being subjected to the worst thing there is, the absolute worst, there will be no relapse. And eternity is a really, really long time. Though someone may spend most of eternity in hell, they still can make it to heaven eventually. It doesn't matter if you're in hell for 148,025,797,359,720,957,280,197,648,021,605,812,604 squillion years, you still get to go to heaven after that. After that long, though, time might have ended. So if time ends and you're in hell, it basically just sucks to be you. Sorry. I didn't say it was a perfect system. Time is relative, anyway. So it kinda can't just end. But anyway, once you are cleansed by hell, you get to go to heaven. Because just like everyone has something bad they've done, everyone has something good they've done as well. And if you have one good thing, then you have the potential and the ability to be good for the rest of forever.
A symbol to represent my hell would be a maze. A really hard maze. It takes you ages, you hate doing it, it's really dangerous, but eventually you make it out. Like the Harry Potter maze. Except you don't get zapped to Voldemort instead of making it out. You actually just get out. And after getting through the maze, even though you feel awful and like you died again (which you already did once, how else would you get to hell in the first place?) you still get the satisfaction of making it all the way to heaven. Everyone can make it to heaven, and that is a good thing, just like everyone can solve a maze even if they hit some dead ends. My hell would be something deceptively simple like a maze but actually be really difficult to solve, even though everyone can do it and has to do it.
Who is in my hell? Everyone. Everyone is going to my hell. Most people I know personally would make it out fairly quickly though. Some people wouldn't. You know, like molesters and mass murderers and serial killers and stuff. Something interesting about my hell, though, is that good deeds don't get you out any faster. You still have to repent for all of the bad things. There is none of this bail-bond nonsense in hell. Everyone pays with time. Once you get to heaven, the good deeds matter. The best people get to become angels and help run heaven and all that good stuff, and everyone else still gets to go to heaven, which is their personal paradise, so they can't really complain. And this isn't about heaven. It's about hell. But those two are kind of intertwined. Anyway, my point is that everyone goes to hell. But everyone also goes to heaven.