Today I was trying to read Jacques Nomssi comment The last runtime buffer you'll ever need? and found it difficult to read because 90% of the horizontal space was not being used to render the reply. I can think for 2 ways to get around it.
Have a look at what I was trying to read.
I am using a widescreen laptop, so the gray color strips on left and right are as wide as the indented reply.
Method 1 - Viewing as PDF
You can click on "View as PDF" link on right side. The resulting PDF has post as well as contents. The comments are sequential, not indented, so they are easier to read.
Method 2 - Removing the CSS styling
In Firefox Menu > View > Page Style > No Style option can remove the styles using which content is positioned in web page.
Some indentation is still there, which is good for readability, and space previously occupied by gray strips and right pane is now recovered.
It now shows me clean text, smiley and images.
There are bookmarklets like readability and readable too that can be tried.