Kun_ :
Gingerbread :
Well I would always get the 6600k with a Z170 motherboard, overclock it and watch it shit on the 6700 in 90% of the occasions.
does it really need to be a superior mobo, like Maximus Hero? or just use the z170 Gaming Pro by Asus
Once you get to Z170 level of board, it really comes down to personal preference. For example, do you need a certain number or SATA ports? Or a certain amount of USB 3.0 ports? Do you prefer vertical or horizontal facing SATA ports? Which colour scheme do you prefer? etc etc
Any z170 board would be a good choice, as long as it's got what you want