A VR road simulator I developped with the help of a 3D artist friend (http://2a3dartist.com/). There was an important time constraint (< 3 months, part time), but it's now used every day to treat dozens of patients suffering from dizziness ! How cool is that !
I did everything related to programming, effects and audio; some cool stuff:
The world is built upon small 100x100m blocks (slope up, slope down, left curve, right curve, same thing with tunnels ...etc) that are then assembled at runtime depending on user parameters ! You could call it "hand made streaming" I guess.
Fully dynamic and intelligent AI traffic; it even features "bad drivers" (some won't ever go in the right lane, some can overtake using the right lane ...)
Fully dynamic weather: it can be sunny, rainy, stormy, foggy and anything in between
Fully dynamic time of day ! Without using Unity's built-in dynamic GI (to save performance, we're in VR).
Sounds: It was my first working with Audio in Unity and I loved it ! There're multiple sounds for the player's car, the other cars and trucks, ambiences, reverb parameters depending on the environment (tunnel vs outside) and weather.