2. More Interiors
By this, I simply mean that I would like more buildings to be accessible, from a lighthouse to skyscrapers and everything in between. Now, I'm not saying I want every house to be unlocked or every floor in a hospital, but then I'm not against that either. GTA IV lacked interiors, with only a few Burger Shots, the lobby of maybe five unique buildings, your house and an old abandoned Sprunk factory to explore. The game instead really pushed on outside street exploration, but I would like to say not merely, "Wow, that building looks cool", but instead, "Wow, that building looks cool, I wonder whats inside." It would make the game feel so much more detailed and intricate. Imagine being able to use houses as an escape route, running past someone cooking in the kitchen or running around the terminals of an airport. It would make for a far more interesting gaming experience, knowing that nearly everywhere was accessible.