Well, I have asked this same question myself. For the most part, the two criteria you are looking for (being "good" and "quiet") are often found at an acceptable level in the absence of the other. Take your sleeve bearing fans, for example: they're quiet, they're inexpensive, but they don't last too long.
One type of fan that I have heard many good things about are <A HREF="http://www.panasonic.com/industrial/appliance/appliance_fans_panaflo_axial.htm" target="_new">Panaflo by Panasonic</A>. Some people talk about them like Xerox or Kleenex: "You've got yer sleeve fans, yer ball bearin' fans, and yer Panaflo." They probably have some of the most detailed information re: their (<i>oops!</i>) fans that I've ever seen on a manufacturer site. I purchased one myself (120L), and it should arrive today.
They cost a little more, buy they should last you a long time.
Other brands to look into are Enermax and Thermaltake. A lot of people also like Sunon, Delta, and YS Tech. For the most part, to each their own.
Have fun looking around!
VSP
<i>Upon the occasion in which the defecation comes into contact with the oscillating ventilator.</i><P ID="edit"><FONT SIZE=-1><EM>Edited by VulcanSoulPatch on 05/23/02 10:09 AM.</EM></FONT></P>