Hands down, the award for the most violent places in the universe goes to black holes. By definition, a black hole is a object with a gravitational field that is so strong, not even light (the fastest thing in the universe) can escape it.
This definition is often taken for granted, and we don’t interrogate what it really means. However, understanding black holes is crucial because they are the great mystery of physics, uniting the very massive with the very small (or general relativity and quantum mechanics).
Moreover, many scientist believe that black holes are very similar to the Big Bang. Indeed, some physicists believe that, if we were able to understand black holes, we would also be able to understand how our universe formed.
So, in essence, black holes are the most amazing things in the universe because they represent everything that we know and that we don't know. These massive space objects are the final hurdle to creating a grand theory of everything.