If I were to choose to go through one of the seven doors, I would go to Wonderland. One reason I would choose this door is because it is the only door that leads to a place I have heard of, and am somewhat familiar with. When I went through the door, I would probably have no clue what to do at first, because it would be a totally new place that I would not be familiar with. Once I actually knew what to do I would probably wonder around for a little bit and see everything.
picture from here