If you want to place top 5 there are a few things you need to cover. Firstly, you need to make it huge. As cliche as it sounds, bigger is better, and especially when it comes to prisons. Second, you need to do it in a way that no one has. Perhaps make it an abnormal prison. Such as torture chambers, hidden pasages, towers, and fire rooms. The third thing is redstone. Try to stay away from regular doors and use more piston doors. A lot of work goes in to a top 5 map. It isn't something you will do over night, or even in a week or two.
Good luck