10. Fallout 3
I felt like this was a good way to open up the list. I could have gone with a few games on this one, but then again, it's not really about the game itself. No, this is about the scope. Scope is something that isn't necessarily new to gaming, but had become a major component to the gaming experience with this generation. Every developer was trying to one-up the other when it came to scope. One might make a game with a huge map, the next will make a game with the same size map; where the previous world might be empty though, and this one may be inhabited. Where Fallout 3 fits into this puzzle though is that it was one of the first that didn't bother easing you into the world. It didn't bother showing you around while you did mandatory "side-missions". Do you remember that first time you got to the door of Vault 101? You open that door and everything is blurry for a second, but within a few steps of exiting, you see this grand world. Sure, it's a void, and everything that moves is going to try and kill you, but the scope alone made me have to take pause. Other games may have been bigger, wider, more colourful... But Bethesda truly opened up the floodgates with Fallout.