[Snowflakian]

Japanese toys tend to scream accuracy, but they are also a more collector driven market, so I'll exclude them from my choices first.

After that, I'd have to say Transformers Animated, followed by GI Joe 25th Anniversary figures, and then Inhumanoids.

These have the best mesh of accuracy to articulation and detailing for animation property toys.

MU is quickly catching up though as they do animation 3 packs, and other figures. So I'll even include the Firestar 3 pack in that.

Toy Biz era Marvel lines get skipped because of MU, and because of other drawbacks to their usage.
And bandai of america still needs to learn how to use articulation and consistency. =/