Chrome on Windows doesn't use the DirectWrite text rendering engine as opposed to Firefox or IE. See details here:

http://eligrey.com/blog/post/better-font-smoothing-in-google...

This has been an open issue since 2009. I'm surprised it still hasn't been fixed even though it's a daily nuisance in the world of beautiful web fonts and large type sizes:

http://code.google.com/p/chromium/issues/detail?id=25541

http://code.google.com/p/chromium/issues/detail?id=105944

EDIT: an official DirectWrite port of Chrome/Win is currently under development:

https://groups.google.com/a/chromium.org/group/chromium-dev/...