It's been a while since we've come across a system buyer's guide but today AnandTech has a new article dedicated to creating a good mid-range system with today's hardware. You can read it over here.
As with the budget segment of the DIY computer market, the midrange segment has seen many exciting new developments since the start of 2012. Perhaps the most noteworthy change is that Intel CPUs are now entirely dominant in systems that will set you back about $1,000. Ivy Bridge-based chips are now available at every price point from $100 up, leaving only the pure budget category untouched (at least until we see the Celeron IVB part). If you're interested in more information, we have a lot of information available on Ivy Bridge..