I will dread to see that happen. If the sun were to just mysteriously disappear, it would mean total darkness. Although not immediately since it takes almost nine minutes for sun rays to reach our planet earth. Further more, the sun is like this mass of gravity that holds the planets revolving around it. So if the sun just disappeared, earth and other planets will probably bounce somewhere into space.
It is also safe to say that it would be mass extinction if the sun just vanished. If every living thing doesn't freeze to death from extreme drop in temperature, we would starve to death. The sun is the central system where all energy comes from. Photosynthesis would have long seized. Plants won't be able to use up sunlight to produce food. They'd die. This means all secondary consumers including man will have nothing to feed on and would subsequently die off.