EF (and EF-S) lenses with the best microcontrast?

[CanNotYet]

So, since I've heard this term "microcontrast" now for a while, I thought I'd start a thread comparing and describing the EF mount lenses (Canon or 3rd party) with the best microcontrast.

As I understand it, this characteristic of a lens is essential for birders and pixel-peepers?

Please, educate me and others on the forum on this topic.