I'm new to this, so tell me if I'm breaking any rules and I'll update it.
CPU: Intel Core i5-4590 3.3GHz Quad-Core Processor ($159.99 @ Micro Center)
Motherboard: ASRock H97M-ITX/AC Mini ITX LGA1150 Motherboard ($79.99 @ Micro Center)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($59.99 @ Newegg)
Storage: Crucial MX100 128GB 2.5" Solid State Drive ($62.99 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($43.79 @ OutletPC)
Video Card: XFX Radeon R9 290 4GB Double Dissipation Video Card ($242.98 @ Newegg)
Case: Antec ISK600 Mini ITX Tower Case ($29.99 @ NCIX US)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Newegg)
Keyboard: Logitech Corded Keyboard K280e Wired Standard Keyboard ($14.99 @ NCIX US)
Mouse: Logitech M510 Wireless Laser Mouse ($24.99 @ Amazon)
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-11 20:09 EST-0500
I'm assuming this is built for a girl, from the title, but I guess I could be wrong...
CPU: Went Intel because I planned on having a dedicated gpu, and the i5-4590 is such a good deal at $160.
Mobo: Went itx, as most of my female friends aren't looking for a large rig to put on display, but instead something small to tuck away. H97 because the CPU can't overclock. Most important feature is the ac wireless connectivity. Having this built in is useful, and I have never met a girl with her router anywhere near her desk.
RAM: Just the cheapest 8 gig kit I could find, just happened to match the Mobo.
Storage: SSD + HDD combo is basically required if the budget can afford it. Makes everything so much better. I know there are cheaper SSD's but Crucial builds fast and reliable stuff and there is no need in cheaping out on your personal data (especially when it's someone else's data).
GPU: 290 is now the best thing for your money. Yes, it will get a bit toasty in an mitx chasis, but there is no better value. Spent the extra $3 on the XFX instead of the MSI solely because I had extra budget and it color matched better.
Case: I personally love the look of this case. It's clean and small, with nice brushed aluminum. And yes, the PSU does fit with the GPU, I checked.
PSU: EVGA makes good stuff. While this is not their best, for a non overclocked build it will do just fine for $30.
Keyboard: Every single time a girl uses either my or my friends mechanical keyboard, they say that they would rather use their laptop's keyboard. So chicklet keyboard it is. I've never used a bad logitech product, so this will definitely not cause any problems.
Mouse: M510. I love this mouse. Used it for ~3 years before upgrading to the G602. It's wireless, with insane battery life (I literally change the batteries once in the time that I used it), no tracking issues, feels great in the hand, has a satisfying click... I can't rave enough about how good this mouse is, especially for being only $25. Best budget mouse IMHO.
This is a bit beastly for a "light gaming" rig, it's amazing how far $750 goes...