The MSI Z170A SLI Plus is a full sized ATX board with a lot of space on it, providing not only nice clean looks but also space for air to flow around components.  It is available for around $140, a decent price for the feature set it comes with. There are three x16 PCIe 3.0 slots, six SATA 6Gbps and an x4 M.2 slot which will accept U.2 with the proper adapter and a USB 3.1 Gen2 Type-C port offering the full benefits of the new standard.  The Tech Report loved the simple design of the board and were more than impressed with the manual overclocking potential; check out their full review here.

"MSI's Z170A SLI Plus is a mainstream board that gives builders everything they need and nothing they don't—at least on paper. We reviewed this board to see whether its real-world performance lives up to its promising spec sheet and relatively friendly price tag."

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