I heard that galaxies have such little densities of stars that the collision of the galaxies will cause relatively few collisions of stars. So we may be lucky there (although by then the sun will have swallowed up the earth already, right?)
Our galaxy and the Andromeda galaxy will merge in a few million years time. However, galaxies colliding are pretty boring. There is so much empty space that the stars will mostly not even get near each other. The gas in the galaxies though will collide and become super bright, so the galaxy(ies?) will become a much more colourful place.