Aliens who have taken traits from their host such as warriors/drones, Runners and Predaliens are not true hybrids as that is simply how all xenomorphs breed, by impregnating a host and absorbing useful traits from the DNA.
Ripley 8 and The Newborn were true hybrids as they were the product of a cloning process mixing up the DNA. To a lesser extent, the Drones and the Queen in Alien: Resurrection were hybrids as they were mutated to the point where their behavior changed.
The hybrids were aliens capable of impregnating "normal" aliens. They were white in color, had mandibles and presumably human intelligence.
Newborn was the result of a queen giving birth. The Newborn had human-like skin, eyes and a tongue instead of an inner jaw. The newborn possessed tremendous strength, as it ripped the queen's head off and crushed a man's head with ease.
Ripley 8 was an imperfect clone of Ellen Ripley, they share the same appearance but Ripley 8 has a completely different personality. She is stronger than normal humans, heals quickly and has acidic blood.