looking at this one:
http://www.pbase.com/fhhecker/image/108672512the histogram shows 1 pixel at 247 as the brightest I could find, the bulk of the image data stops at around 80 (the lower 1/3 of the histogram), with the bulk of the image luminance values (16.6%) at 0
so
this means nothing if you're happy with the images yourself!
I tend not to rely on an OS as a measure of anything as subjective as whether something looks good, but I'm using various flavours of Windows
a - monitors are Trinitron and LG LCD.
Note that using a new mac OS with Quartz 2D through 3D rendering or Vistas equivalent, it will 'spice up' an image and will not show the image data as it really is, so under those circumstances if you're seeing the image and it looks good, it may not actually be as good as you would think (a curse for image editors and greaphic designers!)
k