Perverseness top tier joint is always ball. Ball joint is absurdly erotic, why do you think I have massive ball joints for my hips? It's for the sex appeal, it's to let you know I'm a little freak and you should feel uncomfortable around me. But I don't have double-ball joints, I wouldn't go so far as to expose you all to that and make my company ravenous.

In reality the joint itself is kind of secondary to the mechanism that operates around it. The exact function of a joint is more determined by the engineering requirements. Ball is good because it's very compact and mysterious. A ball joint just works, you don't think about what's operating it very much cause you just see the pleasant round casing and assume something is going on inside that makes the magic happen.

But you're basically masking a hinge or a wheel or something, you know?

Two types of joint mechanisms I really like are fibrous muscle and bare hydraulic, basically for similar reasons. If you can identify that either of these are being used, it usually means there's a gap in the shell somewhere, usually to let the shell pieces move.

Fibrous powered joints are basically like having raw sinew exposed on skin but they can be various colors and thicker strands and either more uniform or heavily layer and complex like human anatomy. It's neat. It can be pretty horrific, it is sort of like looking at the human anatomy and going "but mine is better."

Similar sake for hydraulics, but I think they're more cool than sexy -- but that might also be because I associate them so strongly with the T-800. Like, look at the HotToys T-800 figure and just kind of marvel at the the details, like the thighs being around 3 pistons, and the shoulder joint being a plate that multiple hydraulics pivot to make realistic motion possible. I absolutely was missing that sort of considering on my design for a while.

Special shoutout to when the joints have fabric dust covers. They're a special kind of perverse, which is why they're around my armpit lmao.