The fans that come with your computer are probably bland and cheap, so you may be tempted to buy something a little nicer. LinusTechTips tested premium Noctua fans to find out if they actually kept their computer cooler or quieter.
While the fans did produce a slightly cooler, quieter system, the difference was quite small. Their CPU's temperature only went down by 2C, and the noise level only went down by about 2dBA. So they probably weren't worth the extra money.
Note, however, that your mileage may vary a bit. Their system was water cooled, which relies on fans, but probably not as heavily as an air-cooled system. Furthermore, not all "premium" fans cost as much as theirs did. But, unless your case came with no fans whatsoever, you're probably fine sticking with what you have — unless, of course, you want fans with fancy lights for the sheer bling factor. Check out the video above for more.
Premium PC Cooling Fans - Are They Worth It? [LinusTechTips]