I hate noisy computers and if Macs were noisy then I probably wouldn’t use them… though I do recall my old PowerMac G5 when the fans took off would not be out of place at an airport!
I do remember in a previous job, a user bought their cheap (PCWord Advent) laptop into the office to have something checked, and when we switched it on, it was so noisy. Drowned out all the other office machines… at that time we had four Sony VAIO desktops, an iMac and a G5 PowerMac in the office. The Sony VAIO desktops were quite quiet.
Another time I was testing a Windows Media Centre from Evesham. This was a computer designed to look like a VCR/DVD player and sit under the TV. I was setting it up at home under the TV when I switched it on and my wife said “there is NO way that is staying in here”. It was one of the noisest computers I had ever heard. Couldn’t believe it as it was designed to be a computer to play back music, tv and video. There was no way you could appreciate any music or soundtrack with the noise of the fans!
Another noisy machine was the xBox 360, it’s a lot noisier than either the Wii or the PS3.
I like my nice quiet iMac.
Though my MacBook Pro does get quite loud if it gets hot!