Example depending on the orientation of an enemy the grapple animation changes. Front, sides and back should have unique animations. Maybe even finisher strikes.
Also make it so that when you shoot enemy AI they have more reactions to getting damage because right now they have the reactivity of log. Shooting them in the legs causes them to trip (a stumble for elites, normal AI could go to the ground after enough damage is done to their legs) , shooting them in the shoulder or arms causes them to stop shooting for a second and shooting them in the head has a unique head explosion (really register them head shots). Maybe tripping standard AI could even lead to a special ground finisher.
This is just really about wanting to see new animations in the game that aren't cutscenes or bosses (mini or otherwise).
P.S. Add more types reload animations. Over half the cast share the same reload animation.