For a basic no-frills motherboard that overclocks well and can do 2-way SLI/Crossfire, the cheapest options IMO are the Asrock Z87 Extreme3
and Gigabyte GA-Z87X-D3H
. They're in the $130 neighborhood.
... and if you're not going to overclock much or run SLI/Crossfire, you could go even cheaper than that.