I'm gonna have to say Ryan's, for me at least. The 6700K will last for years to come, The GTX1080 is probably the most powerful single-card solutions on the market today, and one of the best bang for the buck high-end cards. 16GB DDR4 RAM is plenty for modern gaming, and I have a thing for Mini-ITX cases. The liquid cooler, 3.5TB of storage, and the M.2 drive are what really set this build apart for me, as they are powerful solutions that none of the other builder's managed to fit into that form factor.
PCPartPicker part list / Price breakdown by merchant
I'd say that this is a pretty good place to start. Optionally, you could wait for the Nvidia GTX1070 for even more performance, but this is a good upgrade if you want to build right this minute.
What kind of budget do you have? What is the primary use if this computer?
The first place to look if you're gaming is your graphics card.
While I agree with most of what he said, Far Cry 4 was patched to run on dual core processors. That being said I'd still take an i3 over a G3258 for future performance. Especially with Broadwell CPUs releasing in the near future.
Many Linux distros have a normal UI, and Ubuntu based ones are very user friendly, and have a decent number of Steam games available to them.
I've never tried it, so take everything I say with a grain of salt, but from what I hear you'll need an after market cooler. Cooler Master and the NZXT Kraken coolers are supposed to be good coolers, with the Kraken being a water cooler, while Cooler Master makes air coolers.
Haswells will fit, and the Broadwells might, but if I remember correctly the Skylake processors won't
Or you can go with Linux, which is getting more and more games.