Depends a bit on how much you want to spend. Above a certain pricepoint comfort (proper pads and no excessive clamp force) is pretty much standard for any decent brand (that excludes the usual suspects like beats).

Generally full-size (circumaural) headphones should be most comfortable with glasses. Thicker/softer pads and glasses with smaller frame (though you probably won't change that) -> more comfortable.

What are your current headphones?

Form factor doesn't affect performance at all. You lose a PCIe slot, but unless you wanted go Crossfire you wouldn't need it anyway.

For memory 1600MHz CL9 is indeed enough, the 1866MHz CL10 is a bit better and 10$ cheaper, that's 10$ more you can spend on other stuff (e.g. the GPU).

The 270X and 270 are identical except for the clockrate. In this case the difference should be 10-15% and it's only 10$ (=5%) more so why not.
There's also this one
http://au.pcpartpicker.com/part/xfx-video-card-r9270xcdbc
Another 10% for another 10$. Wasn't sure about shipping and your budget so I didn't include it the first time.

You could also get the Xeon E3-1230 v3 (I love that thing, think i7 without iGPU for 100$ less) which would put you 1$ over budget without shipping with the 270X or 9$ below with the 270.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E3-1230 V3 3.3GHz Quad-Core Processor ($279.00 @ CPL Online)
Motherboard: ASRock B85M Pro4 Micro ATX LGA1150 Motherboard ($84.00 @ CPL Online)
Memory: Kingston Fury Black Series 8GB (2 x 4GB) DDR3-1866 Memory ($89.00 @ PLE Computers)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($62.00 @ Centre Com)
Video Card: XFX Radeon R9 270X 2GB Double Dissipation Video Card ($209.00 @ PLE Computers)
Case: Cooler Master N200 MicroATX Mid Tower Case ($49.00 @ PCCaseGear)
Power Supply: Corsair CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply ($69.00 @ CPL Online)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($19.00 @ CPL Online)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($115.00 @ CPL Online)
Monitor: BenQ RL2455HM 60Hz 24.0" Monitor ($199.00 @ CPL Online)
Wireless Network Adapter: TP-Link TL-WN881ND 802.11b/g/n PCI-Express x1 Wi-Fi Adapter ($18.00 @ CPL Online)
Keyboard: Ducky Zero Shine Blue LED Keyboard Wired Gaming Keyboard ($109.00 @ CPL Online)
Total: $1301.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-11-20 19:03 EST+1100

i3-4130T = low power version of the 4130. Worse performance and a lot more expensive.

What's your budget?

A few minor tweaks:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor ($219.00 @ CPL Online)
Motherboard: ASRock B85M Pro4 Micro ATX LGA1150 Motherboard ($84.00 @ CPL Online)
Memory: Kingston Fury Black Series 8GB (2 x 4GB) DDR3-1866 Memory ($89.00 @ PLE Computers)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($62.00 @ Centre Com)
Video Card: XFX Radeon R9 270X 2GB Double Dissipation Video Card ($209.00 @ PLE Computers)
Case: Cooler Master N200 MicroATX Mid Tower Case ($49.00 @ PCCaseGear)
Power Supply: Corsair CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply ($69.00 @ CPL Online)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($19.00 @ CPL Online)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($115.00 @ CPL Online)
Monitor: BenQ RL2455HM 60Hz 24.0" Monitor ($199.00 @ CPL Online)
Wireless Network Adapter: TP-Link TL-WN881ND 802.11b/g/n PCI-Express x1 Wi-Fi Adapter ($18.00 @ CPL Online)
Keyboard: Ducky Zero Shine Blue LED Keyboard Wired Gaming Keyboard ($109.00 @ CPL Online)
Total: $1241.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-11-19 21:15 EST+1100

Some more case options:
http://au.pcpartpicker.com/part/silverstone-case-ps08b
http://au.pcpartpicker.com/part/fractal-design-case-fdcacore1000usb3bl

#297
Depends on which PSU we're talking about.
If you decide to go for a new PSU I'd recommend this one http://pcpartpicker.com/part/evga-power-supply-120g10750xr
What about the mobo, do you need 8 SATA 6Gb/s ports?
There's also better and cheaper RAM. Even if you want a bit more performance than the standard 1600MHz CL9 there are better options than 1600MHz CL8 (e.g. 1866MHz CL9).

#298
Why the T SKU?
What is your performance goal/intended usage?

#293
No new cooler needed.
What are you going to use it for? Especially the 16GB RAM.
SLI planned or why the 750W PSU?

#294
Pricing and availability change at least weekly, logicalincrements (see #295) already provides a guideline/base build but any special requirements and current pricing need to be looked at for each build individually within one or two weeks of the purchasing.

#290
I'd go with IPS if you can live with 5-8ms response time instead of 1ms, the colours and viewing angles are just so much better. Otherwise it seems like a decent monitor. I'll look up prices and availability in the US for some monitors and recommend one as soon as I got a little more spare time.

#291
CX430M is a good budget option (although PSU prices are doubled in AUS because Aussie reasons).
Antec HCG-520M is an option aswell, excellent ripple supression, a bit higher wattage, but a little bit more expensive and slightly worse voltage regulation.
CS450M about the same price as the Antec. Only slightly better ripple supression than the CX430M, Gold efficiency though.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($279.00 @ CPL Online)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($37.00 @ CPL Online)
Motherboard: ASRock Z97M Pro4 Micro ATX LGA1150 Motherboard ($129.00 @ CPL Online)
Memory: Kingston Fury Black Series 8GB (2 x 4GB) DDR3-1866 Memory ($89.00 @ PLE Computers)
Storage: Samsung 840 EVO 250GB 2.5" Solid State Drive ($135.00 @ Mwave Australia)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($62.00 @ Centre Com)
Video Card: Gigabyte Radeon R9 280 3GB WINDFORCE Video Card ($249.00 @ CPL Online)
Case: Cooler Master N200 MicroATX Mid Tower Case ($49.00 @ PCCaseGear)
Power Supply: Corsair CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply ($69.00 @ CPL Online)
Optical Drive: LG GH24NSB0 DVD/CD Writer ($19.00 @ CPL Online)
Monitor: BenQ XL2411Z 144Hz 24.0" Monitor ($399.00 @ CPL Online)
Total: $1516.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-11-14 19:41 EST+1100

micro-ATX
Both the mobo and the PSU will make Crossfire/SLI impossible, the budget would allow it but I think it's unnecessary.
The RAM is only worth it if shipping is less than about 6$. Otherwise http://au.pcpartpicker.com/part/team-memory-tzbd38g1600hc9dc01
Added an SSD.
Getting the HDD from CPL Online will add 1$ but should reduce shipping cost.
R9 280 > GTX 760, unless you're using Linux/SteamOS. If you think you'll play a lot more demanding games than TF2 (or want 120fps in every game on high-max settings) you could drop the SSD to 120GB and get an R9 290. You might want to go with the CS450M or HCG-520M if you want to overclock 290, it can draw a lot of current.

Buying a 2500K or 3570K is retarded. Haswell (4xxx) is newer and faster at the same price.

Budget?

You could've put this in the pc build thread btw.

4690K and H97? Not sure if I like that.
Enermax ETS-T40-TB is cheaper than the 212 Evo right now and performs a lot better.
Forget Corsair RAM unless you like overpaying for useless heatspreaders. Overpriced and highest RMA rate.
280X is cheaper and performs at least the same if not better. Only applies if you're not using Linux/SteamOS obviously.
NEX 750W 20$ mail-in rebate right now. Cheaper brand new multi rail FSP model vs an older, already discontinued (original Hive series is that old), single rail Sirtec PSU. 200W more is a bonus.
CX430M is a decent budget option.
Mobo with Wi-Fi is cheaper than buying seperately.

Cheaper build (mini-ITX):
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4690 3.5GHz Quad-Core Processor ($209.99 @ Amazon)
Motherboard: ASRock H97M-ITX/AC Mini ITX LGA1150 Motherboard ($84.99 @ Micro Center)
Memory: Team Vulcan 8GB (2 x 4GB) DDR3-1600 Memory ($68.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($53.68 @ Amazon)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($209.99 @ NCIX US)
Case: Cooler Master Elite 120 Advanced (Black) Mini ITX Tower Case ($37.99 @ Micro Center)
Power Supply: EVGA SuperNOVA NEX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($39.99 @ Newegg)
Monitor: Asus VN247H-P 23.6" Monitor ($164.30 @ Amazon)
Total: $869.92
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-11-13 03:38 EST-0500

Improved and still cheaper (micro-ATX):
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor ($214.29 @ Amazon)
CPU Cooler: Enermax ETS-T40-TB 86.7 CFM CPU Cooler ($29.75 @ Newegg)
Motherboard: ASRock Z97M-ITX/AC Mini ITX LGA1150 Motherboard ($103.91 @ Newegg)
Memory: Team Vulcan 8GB (2 x 4GB) DDR3-1600 Memory ($68.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($53.68 @ Amazon)
Video Card: Asus Radeon R9 280X 3GB DirectCU II Video Card ($209.99 @ NCIX US)
Case: Fractal Design Core 1300 MicroATX Mini Tower Case ($39.99 @ NCIX US)
Power Supply: EVGA SuperNOVA NEX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($39.99 @ Newegg)
Monitor: Asus VN247H-P 23.6" Monitor ($164.30 @ Amazon)
Total: $924.89
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-11-13 03:50 EST-0500

ATX option for mobo: http://pcpartpicker.com/part/asus-motherboard-z87pro

I can't write down all the pros and cons of lightboost everytime I comment on a monitor having/not having lightboost ;-)
OP compared it to monitors with lightboost so I had to mention it. Can't compare something if you ignore the differences.

Not sure how the slower gtg is relevant, motion blur comes mostly from persistence on fast LCDs. Otherwise strobing wouldn't make sense.

Warm up is perfectly normal.

No Lightboost.
Colours are a bit better than the ASUS VG248QE afaik.

#284
Budget?
CPU: 4670K is retarded, you can't overclock with such a small cooler and even a 50$ CPU would be enough.
Mobo: ATX mobo severly limits your case choices and takes up a lot of space.
RAM: Thought about ZFS? You might want ECC.
SSD: MX100 is probably better today, wasn't released back then so I can't blame the guy.
HDDs: fine
GPU: Hilarious overkill. A HD6450 a passively cooled 30W card for 30$ can handle the hardware acceleration for 1080p playback. No need for a 150W card for 160$. If you want to go overkill get a 750 or 750 Ti. Still overkill but cheaper and only 40W, even overclocked only 60W -> damn near silent.
Case: Seriously? 152$ for a HTPC case?
PSU: Non-modular PSUs in small cases are always fun.
OS: I see the point of the Pro version though I don't see the point of windows itself.

If HP Microservers weren't so expensive in the US I'd recommend that. Over here I can get one with 4GB ECC for 150€, +50€ for another 4GB, +100€ for GPU and ODD, that's <400€ for everything but the Storage. Small OS -> Flash Stick works fine, +420€ for the HDDs
-> ~800€ total

How is the case size relevant?

GPU is fine, even onboard is enough for TF2

TF2 loves high clockrates -> overclocking. Neither your CPU nor your mobo can do that.

If you're lucky you might be able to find a used 2500K/2550K/2600K/2700K + mobo for 200-250€, but that's about it. Anything else isn't going to be an upgrade or will be even more expensive.

E3 1230 and 1230 v2 should be compatible, depending on how fucked up TF2 is for you, you'll get either 0%, ~30% or ~100% more fps.

Looks like 21:9, probably 2560*1080.

Just post again or send me a message less than a week before you buy it and I'll make an updated partlist with the current deals.