Noctua and Scythe make good fans but are kinda pricey, I find yate loon fans work great for 1/10 the price of a noctua or scythe. It really depends on what you want to spend and how tolerant you are of noise, some fans have great airflow but sound like a jet turbine.
get a high CFM rating on the fan if you dont care about noise. but make sure that the output of the case fans can match close to that, or the fan will continue to blow hot air over something that's already hot.
I like quiet, so I have a Noctua fan on my TRUE. The Scythe is also good, though it seemed a touch noisier. Could be just a different pitch that got my ears attention and not the decibels. Don't know.
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Evil lurks in the databanks as it lurked in the streets of yesteryear. But it was never the streets that were evil.
well the best fan, hands down would probably be the Delta GFB1212VHW 120x76mm Very High Speed on this page http://www.sidewindercomputers.com/120mmfans.html . ha keep in mind this fan is not quiet but you mentioned nothing on noise in your original post.
