I've been trying to fix this issue on my Windows 7 rig for months. Messing with the ClearType settings appears to work, but the first time you restart your computer after that, it reverts to the poorly rendered fonts. There doesn't seem to be any intuitive way to make the ClearType settings sticky :-\
However... disabling 'Accelerated 2D canvas' in the chrome://flags finally did the trick. This makes total sense, because it's my PC at work that exhibits the problem, and it of course has a bottom feeder of a graphics card. My gaming rig at home, OTOH, has a top-of-the-line NVidia card and doesn't have this problem.
You're a star, Mike.