So this is my first ever build. I came from playing on a Asus g74sx gaming laptop that had a GTX 560m which played most game pretty well on medium, but since I love my graphics I felt I needed to upgrade. The one main use of this machine is purely gaming. I'm still in the process of getting new fans the replace the stock fan, and I'm getting some lighting for the case as well as sleeved cables.
The case: So I went with the Corsair 750D due to the nice sleek look of it, the massive side window so I can show off everything and because of the amount of space inside the case. It was my first build so I liked having lots of room to route cables and fiddle with stuff. Overall, great case.
MOBO: I chose the Maximus VI Hero because is seemed like a not too high end, but no too low end motherboard with a decent price range. No problems with it so far.
CPU: Many people say that you don't need an I7 for gaming, but I just went with it due to it being in my price range. I do a little bit of video editing and the occasional 3D editing, so it'll help in that department. Went with the K version so I can OC in the future.
CPU Cooler: EDIT: Now in Push/pull config. Main reason I went with a AIO cooler is due to looks. I really don't like the looks of air coolers, they just look bulky and ruin the looks of inside the case (especially with the window on the 750D). I wasn't keen enough to do proper water cooling yet, so the H100i was a good substitute. One problem with the H100i is that the pump is a tad loud. It sounds like a small but noticable humming sound like a fan would make. Not sure if it's normal.
GPU: I was umming and ahhing about whether to get the EVGA 780 or ti version. For an extra $200 for the ti I believe its worth it. I'm running 2560x1440p, and whilst playing BF4 on ultra settings i was still getting around 70-80 fps. Temps get to around 68-70, depending on fan speed and ambient temp. It does blow a lot of hot air straight into the case window, heating it up a bit, but it only ever gets slightly warm. The 780 backplate also fits on the 780 ti. It gives it a really nice look instead of the ugly PCB.
RAM: Went with 2x4gb Corsair vengeance. Didn't look to much into it, just say they had good reviews. Will probably get 2x8gb when I need it. (which won't be soon)
PSU: I got a 860W power supply so later down the track I can sli. The modular cables are really handy for cable management, keeps the case looking clean. This PSU has 7 years warranty so thats a bonus too :)
SSD: Can't believe I've been living without an SSD for so long! The boot times and load times of games and apps are amazing! Takes under 10 second to boot with everything up and running, games load 3x quicker. If you don't have one yet, go buy one!
HDD: This part is pretty simple. 2TB hard drive for most of my games to be installed on, will be getting another one later down the track
Monitor: Going from 15.7" TN 1600x900p, to 27" PLS 2560x1440p is just amazing! I'll never go back to anything under 1440p, I just couldn't cope, and the PLS screen look really good! One problem with the monitor is back light bleed. I have yet to take it back to get it fixed/replaced but I will be in the future.
Keyboard: I chose to go with the Steelseries APEX due to it being like a laptop keyboard (which I like the feel of). The keys are low profile, not too hard to press down and feel good when typing or playing games. The size of the keyboard is nearly as wide as my monitor, so it's pretty big! Lots of macro keys, nice illumination. Overall good keyboard.
OS: I got my OS free from my school. We got Win 7 Ultimate, and Win 8. I chose to go with Win 7 because I don't like like Win 8 much. I havn't used Win 8 much but from what I have used, Win 7 is a better pick.
Speaker: I actually won that speaker from an EB Games competition for Modern Warfare 3. All it is, is a PA system with a few modification to the looks. It works really well and I've been using it well before this build.
Headset: I bought this headset for my Ps3 about a year ago for $350. It's an Astro A50 headset. It very comfortable to wear, and doesn't slip off your head. The audio quality is what you'd expect from a $350 headset, amazing! The base is good, nice controls for having voice chat over game volume or vice-versa.