For a few years I have been using a Coolermaster Elite 120 mini-ITX case to house my PC. It has been a great case, and you can build a monster system inside a tiny case. I use my pc in the living room, on the TV, so it had always been a necessity to use a small case that can be somewhat inconspicuous. Ive had many rigs in it, from the orginal a10-6800k with no graphics card, an i5 system, and now the i7-6700k and 1070 setup, even overclocking. Needless to say things got quite cramped.
Even with this cramped setup, my overclocked cpu never exceeded 80 Celcius, which is within operating standards. Nevertheless I decided to see what a proper case and cpu cooler would do. So I picked up an NZXT S340 case and a Hyper 212 cpu cooler. The difference was drastic. While playing DCS, my temps never exceed 60, staying in the high 50s. So it was a good 15-20 degree drop over the cramped setup.
The case is cavernous with a mini-ITX board in it. Reminds me of when I moved to my 2nd house, which was about 1500 sq ft larger than the last, and my furniture looked ridiculous in it. Need to do some cable management and I’ll be good to go! Highly recommend the case and the cooler, they were pretty cheap as well. Got the cooler for $17, and the case for $55.