I'd been using an old Dell XPS 410 for the longest time, and after five and a half years and numerous upgrades to the ol' Dell, I decided it was finally time to step up and build an entirely new computer. The only catch: it had to be under $500 at the time of purchase (came to $495 and change when bought on Black Friday). That said, I feel like I made the most I possibly could out of the budget given, and I'm quite satisfied with the result.
Let me know what you think! Comments, questions, concerns, they're all welcome.
edit: Looks like I've won the silicon lottery; I've been able to overclock my CPU to 4.2 GHz. Bought a Cooler Master Hyper TX3 just to be safe, alongside a DVD drive.
This CPU won't set any world records for speed, but for around $70-75, you can't beat it with a stick. Plays stuff like TF2/GMod/LoL maxed out with power to spare, and will probably run newer titles like GTA5 at decent settings too. Just don't expect to max out Fallout 4 with it. Temperatures are also surprisingly good with the stock cooler, at 31 degrees Celcius at idle and 51 degrees under heavy load according to HWMonitor (though the stock cooler does get pretty loud when stressed, I recommend something like the Cooler Master Hyper TX3/T4/Hyper 212).
For the price, this cooler's quiet and cools the CPU nicely. My one issue with it (and it's a biggie IMO) is the installation: the included clip for AMD motherboards is one of the most frustrating things I've dealt with in some time. Because it kept falling apart, it took me five tries to get it installed, and each failed install required me to remove/reapply thermal paste. Cooler Master ought to find a way to make a better clip.
Was right around $60 when I bought it, and it's simply great. Excellent build quality, lots of SATA ports (eight of 'em), and supports CrossFire if you're running Radeon graphics. Bonus points for working perfectly with Linux, if you're into that (as am I, but I run Windows since not all my Steam games have a port yet).
Cheaper than the standard Ballistix Sport when bought, and comes with snazzy blue heatsinks. RAM is RAM, for the most part, just get whatever's cheapest from a reputable manufacturer.
Previously bought for the Dell XPS 410, this isn't the fastest SSD out there, but for its price, you can't get much better than this. Just works, and is much much faster than a hard drive.
Cheaper than its Western Digital Blue counterpart, and is just as reliable, for the most part. Just don't get the 3 TB version, as it's infamous for failure (and is probably why Seagate doesn't have the best of reputations).
For $140 at time of purchase, this thing is amazing. Compared to the GT 640 I was using in my old Dell, it's like looking into a whole new world! Runs everything I've thrown at it, and I've yet to find something it can't run. An interesting feature is its silent-cooling mode, where the fans don't kick in unless the GPU gets above a certain temperature (around 65 degrees Celcius, by my testing), since the card can downclock itself when not in heavy use to save power.
This is probably, relatively speaking, the weakest part of my build IMO. I do like the minimalistic styling, the front-facing USB 3.0 port, and the fact that it comes with two case fans and actual dust filters, but (and this is why I consider it the weak point) good cable management is a pain with this case! One must be strong and very patient to get the right-side panel back on after routing cable back there. Had to fight it on, and you never want to fight your case. Also, make sure any optical drive you wish to put into here is less than seven inches deep, as some motherboards may be too wide to allow a proper fit.
That all said, however, it's still not that bad for under $50, it's just that you have to keep the drawbacks in mind.
One of the cheapest power supplies you can get that's still made out of high-quality parts. I honestly would recommend this over the omnipresent Corsair 430-watt units I see used all the time. Provides all the juice my system needs, and quietly, at that.
Fit perfectly into my rather cramped N200 case, and functioned immediately out of the box with Windows 10.