It was pretty much just Trespasser and Hitman using ragdoll physics in 2001, wasn't it?
AvP2 had fantastic lighting, but was let down by the art design, which for some inexplicable reason tried to employ a comic-esque style. Hence ridiculous froggy aliens, David Bowie colonists and a general sense of unreality.
But the engine rendered curved surfaces, dynamic lights, and managed long view distances and massive entity counts without excessive frame loss, so the technology itself was fairly sophisticated for the time.