Most popular car companies make some cars that are very reliable and some that aren't so great. You just have to research them before you buy. Typically, anything from GM, Ford, or Chrysler is pretty good (the big 3 American companies). Most Japanese car companies make great cars now too and have for decades. GMC is a truck company from GM, they don't make any cars.
The person that told you Ford is good and stay away from GM and Chrysler is just brand loyal to Ford. This is very common. The truth is, all 3 companies have their good and bad vehicles. Also, how a vehicle is maintained is equally or more important than what it is.