This build is what I'm currently using in my home office. Every part I've included has upgradability and functionality in mind.
The graphics processing is done on an A6-6400k, which takes advantage of a lot of AMD architecture to push out some decent graphics for $50. I can play Battlefield 3 on low, Counterstrike Source on medium, and Hawken on medium with the APU alone.
For the motherboard, I went with the Gigabyte F2A78M-D3H. This motherboard is practically filled to the brim with features. Also, since it's has an FM2+ socket, it will accept the high end AMD A Series APUs for future upgrading. I plan on upgrading to the A10-7870k in the future.
For the RAM, I chose a single HyperX Fury Black 8gb stick. While some may say that you should opt for dual channel RAM, I knew I'd be upgrading to 16gb in the future. Only getting 1 8gb stick will allow me three open slots for a possible 32gb of RAM.
To power this all, I chose an EVGA 430W PSU. While the 500W variant would also suffice, I chose the 430W because I knew I wouldn't need to be pushing much power. It's far more than enough to power the whole system, and likely many low-power graphics cards in the future.
To hold this all, I chose a Thermaltake Versa H25. The case itself has reasonable quality, and for under $45, it's practically a steal. The inside is black, which was one of my main concerns(to make the build look good), and it has somewhat decent cable management in the back. There is a windowed version, but I opted for the windowless version to save $10. The cable management area is a bit slim, so it may require some more effort to route cables.
This is a great APU for an HTPC or budget build. It runs Windows fantastically, and I've found that Counter Strike Source, and Hawken run great on it. I've gotten Battlefield 3 to run on it, but being that Battlefield 3 is optimized for a quad core CPU, this dual core APU had a little trouble with sound and stutters. Don't expect to run AAA games on it, but do expect a smooth performing APU, and smooth 1920x1080 video playback.
This board is filled with features. However, a motherboard is a motherboard. The software that Gigabyte included is a bit choppy, and is always running in the background. While it doesn't hinder performance, I've found the implementation a tad annoying. Besides the software, the BIOS is very nice, and has all the FM2+ features one can expect.
The HyperX Fury Black is some of the best looking RAM that I've come across. It performs without any issues, and looks good while doing so.
The Thermaltake Versa H25 is an average case. It looks good, but doesn't stand out too much. I do enjoy having a USB 3 and USB 2 on the top, alongside microphone in and audio out. However, cable management in this case is slightly annoying. The motherboard sits all the way against the top, so there are no cable routing holes right above the motherboard for CPU power and radiator placement. Room in the back of this case was almost only given by the plate, which raises out towards the center in a sort of house-shaped rise. Other than that, it's alright.
The EVGA 430W PSU is a very good power supply. Coming from EVGA, I expected no less. The PSU itself is also 80 Plus certified, which is a much if you plan on using it for the long haul. Overall, I have no gripes with the PSU other than the cable wrappers are very firm. Routing them through a case may be a bit of a struggle if you don't have ample room to work with.