I love the prometheans in halo 5. They are alot more interactive and in some cases challenging, while the nights are dynamic and require strategy/aim, while in halo 4 they were just lame. Even the movements in halo 5 are great across the prometheans. Driving a warthog through the crowd is the most satisfying thing ever!!! My favorite though has to be the infection forms. As for the ones I hate the most, it would be the halo wars scarabI'd say worst is the Promethean/Forerunner hostiles in H4/5, simply because they're boring encounters.