This made me realize that Far Cry is the only first person open world game/series I can think of. Also the way the minimap moves in relation to your viewpoint is soo good.
Don't forget the Elder Scrolls series.
I can take a lot of enjoyment from a vast, well-designed open environment to explore. Even without the "game" part (conversation trees, combat, crafting) I absolutely adore the feeling of inhabiting a carefully constructed virtual world.