The largest fan possible that fits in your case should be the best buy as far as noise vs CFM / airflow is concerned.
CFM is cubic feet of airflow per minute. The higher the number, the better. RPM is the rotational speed of the fan. The higher this number, the noisier and greater then CFM becomes. Dba is the loudness of the fan. The higher this number is, the more loud. the fan will be.
There are also two different kinds of connectors, 2 pin and 3 pin. 2 pin runs at full speed, while 3 pin fans adjust their speed to match the amount of cooling needed.
Ball bearing is generally accepted as the most reliable and quiet type of fan.
Most cases come with the standard size (80mm / 8cm), but many cases do have 90mm or even 120mm fan bays. It really depends on how your case is made. You can always measure the space in your case for fans and figure out what size of fan you need.
As far as brands go, I haven't had any problems with any fans ever quitting on me except for a couple of antec fans. Not sure if that is a good indicator of "buyer beware" though. Panasonic Panaflo fans are certainly good quality, but I can't really recommend those over any others. I've also been pretty happy with some of my Coolermaster fans I've purchased in the past.
If your case fans quit, I don't think there will be any immediate danger to anything in your system. So don't worry so much about finding the world's most reliable fan. Just find one with good specs (good CFM, good Dba "quietness" and the right size).
Your "typical" 80mm fan has about 25 CFM, maybe 32Dba or so. So you can compare to that. 25Dba and less is considered very quiet. 38Db or higher in my opinion, is very loud.