The two main enemies of all PCs are heat and dust. I know from personal experience not addressing either can lead to fiery results. A simple cleaning every month or so can handle the dust issue, but reducing heat is more complicated. NZXT looks to simplify this with their new FZ-200 Series enthusiast fans.
These massive 200 mm fans can generate up to 103 CFM with only 20 dBA of noise thanks to their high performance design and low operational 500 to 900 RPM. The key here is you can easily replace several fans with just one of these. This will reduce noise and lower voltage use slightly, as well as potentially increase airflow too.
If you need something a bit flashier, NZXT will also be releasing the FZ-200 LED fan in 5 colors. These being white, blue, red, orange, and green to match with most cases on the market. The NZXT FZ-200 fans are available now for $17.99 and the FZ-200 LED fans are available for $20.99.