This was my first build and was a lot of fun; a huge step up from my laptop. Pretty much used exclusively for gaming it runs everything wonderfully at 1080p. The actual build went incredibly smoothly, my attempt at cable management is alright I think, although nothing special.
The parts -
CPU - Intel i5-4670k
I overclocked this to 4.2 GHz, I could have it at 4.4 at the expense of a few degrees, but it didn't seem worth it.
CPU Cooler - Cooler Master Hyper 212 EVO
What can I say that hasn't been said already? It's a great budget air cooler and stays quiet, allowed me to overclock to 4.2 GHz and not get too hot under everyday conditions.
Motherboard - Gigabyte GA-Z78X-D3H ATX LGA1150
Fits nicely and doesn't look as bad as I thought it might. I was tempted by the Asus Z87 Sabertooth just because of how great it looks but honestly for practically half the price this motherboard does everything I need it to. Not to mention that with DDR4 memory being available in the next couple of years I might want to change the board anyway. The BIOS is easy to use and has a decent interface.
RAM - Corsair Vengeance 8GB (2 x 4GB) DDR3
Originally when I installed it it had a default speed of 1333 MHz, so I had to manually set it to 1600 in the BIOS, which was easy. I was going to get 16GB although again with DDR4 being available not too far off, I doubt I'd get use out of 16GB of RAM since all I'm doing is gaming. I would recommend the low profile vengeance RAM though, since I can't install a larger CPU cooler like the Noctua NH-D14 if I wanted to because of the height.
Graphics Card - MSI GTX 780 3GB
Absolutely fantastic card and so happy I got this over the GTX 770, or equivalent like a GTX 760 SLI setup. It wasn't worth it to pay another £200 for the 780 Ti, so I think I did the best I could for the money. AMD was a possibility but the reference cards are so loud and I wanted a quiet build, non reference cards are being released now though so if you're happy with AMD I don't blame you - there are so many great cards to suit anyone's needs. I did overclock it to around 1000 MHz with a boost clock of ~1100 MHz, but this was pretty unnecessary and resulted in an 8% frame rate boost at best. Seeing as games like Tomb Raider and Sleeping Dogs run at over 70 Fps at all times I don't really need to bother with that just yet and the standard MSI gaming app is fine.
Case - Fractal Design R4
We all know it's good (if a little overused), and it met the standards I'd read about - quiet and relatively cool. Had it been available I might have gone for the NZXT H440, but I'm happy with this.
PSU- Corsair RM650
Gold standard and fully modular, runs quiet and efficiently. It cost around £20 more for this version over the CX600, but I'd rather have the extra features for only a little more. My one gripe is the darn ribbon cables, which are annoyingly stiff, still manageable enough to recommend the PSU however.
Storage - 120GB Samsung 840 EVO and 1TB Seagate Barracuda
Fairly standard setup of OS on the SSD and virtually everything else on the HDD, works nicely and I'm happy to pay a bit more for the more reliable Samsung.
So that's the build, it was a great first experience and I'd like to say thanks to everyone on this site for the handy tips that helped me build this. Happy building!