The ultimate collision of our universe is two galaxies colliding with each other. Right now our Milky Way galaxy is on a collision course with Andromeda galaxy.
Two galaxies are travelling towards each other with the speed of 1.5 million km/hour. The collision will take place in less than 4 billion years. That will merge two galaxies into one. A new galaxy will be born with new stars, new planets and hopefully new Earth with life.