Incipio Dual Pro
After looking at several cases, I wound up ditching my Spigen Capsule (not enough protection, IMHO) and getting an Incipio Dual Pro, mainly for the overall protection, especially the nice fat "front lip" which lifts the face-down screen off the surface where the phone rests. I read on some user reviews that the coating on the plastic (it's a two-piece case, hard plastic outside, TPU (?) inside) eventually wears off, but I'll worry about that later.
It doesn't look as nice as other cases out there, but black/black or black/grey are low-key enough to swing it.
I wanted info on the Evutec Karbon Osprey SI case for the 6, namely how much the front lip protrudes from the case, and sent them an e-mail, but never got a response back. Their loss.