Long story short, all of my initial Intel Skylake Linux testing has been done with the MSI Z170A GAMING PRO motherboard, which has been working out well.
I bought the MSI Z170A GAMING PRO when picking up the Core i5 6600K for Linux testing at Phoronix. Leading me to the Z170A GAMING PRO was that it was one of the few motherboards at Skylake’s launch time in sufficient quantities, its priced at less than $200 USD ($170 right now), generally having good experiences with MSI motherboards, and MSI has been friendly with Phoronix and the Linux community in recent times.