I will make the case that the ASRock Z97 Extreme6 motherboard is the best choice because of its feature set and price.
The first thing to note about all boards under consideration is that they are absolutely top-notch. These boards represented the best each respective company could put together when socket 1150 was the leading socket for Intel. In terms of durability, reliability, and manufacturer support, these rank ahead of any other OEM motherboard for this socket in the desktop space. This leaves only price and feature set to differentiate them.
Another poster has recommended the Asus Maximus Ranger vii motherboard. This was a very popular choice in its heyday because it had a good marketing campaign, Asus enjoys good brand rep, and because it was priced intelligently above many of its competitors, giving it the aura of an elite product SKU (which it certainly is). However, I think that for precisely these reasons, it is now certainly not the right choice for you. This board is not in much supply right now, so unless you want to buy used, it will be difficult to procure at a reasonable cost. My recommendation, the ASRock Z97 Extreme6, is still available on Newegg at a very competitive price.
Though price seems to favor AsRock's board, this means nothing if AsRock doesn't bring compelling features to the table. Fortunately, AsRock does. Let's compare (please excuse the crappy pic):
In almost all of the most important ways, these two boards are identical. They enjoy the same chipset, the same RAM slots, the same cooling schema, and a similar audio chipset. The important advantages of the Extreme6 are as follows:
- Dual gigabit ethernet. This allows quite a bit of flexibility and creativity when it comes to how you configure your network - you can even team these connections together to get a better connection to your router, though that's probably not going to help much if you don't also have a teamed connection all the way out to a fiber line - the real joy of having this feature is that the board will remain useful to you as a server after it has ceased being your gaming rig. It also allows you to do neat things like daisy chain an ethernet connection to another PC, or access some kind of network resource like a server, separate LAN, or whatever while not giving up your primary hardline connection to do so.
- 6x USB 3.0 without headers. This is great because it means two more USB 3.0 connections and more longevity in terms of your ability to support modern peripherals.
- Displayport output on motherboard. This is the most modern video out format available, and it is not available on the Maximus.
- mPCI-E port. This gives you access to cheap laptop parts like wifi cards, 4G modems, and GPS units. It represents added versatility over the Maximus.
- Maximum shared memory is more permissive (1700mb vs 500mb); you can attach many screens to your motherboard video outs (especially using DP splitters) without worrying about running out of framebuffer.
- SATA Express connector available, offering compatibility with one of the fastest available connections to external drives.
- More SATA connectors available on a separate controller helps to alleviate potential I/O bottlenecks at the controller level if you install your HDDs intelligently.
- More and faster m.2 connectors - has 2, one of which is the newer, faster Ultra type
- More and more intelligently-placed fan headers. It is worth noting, though, that the AsRock's fan headers are mostly 3-pin, while the Maximus enjoys mostly 4-pin fan controllers, which usually gives the computer access to better speed control for fans that support 4 pin connections.
All in all, I think the features you get with the AsRock board outweigh the Maximus' brand name even at the same price, given that both these boards are well made. The added versatility is something that will make this board a workhorse for you or whoever else owns it long past the days when it can serve as a gaming rig's basis.