The Windows font rendering system tries to aggressively fit typefaces into the pixel grid. This is a throwback to low PPI displays from back in day.
Linux's fontconfig allows for all sorts of configuration. Ubuntu, by default, probably has the nicest config. Otherwise, I personally turn off all hinting but leave subpixel rendering on. Brings it closer to what OSX does.
Personally, the best font rendering I've ever seen is on a high PPI Android phone. Most pages that are more than 2-3 paragraphs I forward to my phone for reading, since my desktop displays aren't that great.
