It's sort of a bad time to try to build a "future-proof" board. The best you could do is an X99 board (if what you're doing benefits from 6+ cores), but even they are almost at the end of their lifespan. The next-gen Skylake is coming out towards the end of the year, and it's not going to be compatible with current-gen Haswell.
What will you be using your computer for, and what is your budget in mind?