[En Sabah Nerd]

Between the 3 species it's easiest to spin the predators as the being the best option. Ever since the first AVP comics there has always been a "hero" predator that works with or at the very least doesn't kill the humans. The aliens are always just savage animals that kill on instinct which makes them the go to bad guys and the engineers while not fully explored definitely harbor no love for any race and seem intent on destroying humans. Predators have an honor system so it's easy to write out a plot where this honor system makes them the alien species we root for.