Warning: I don't know the whole story about this (no warranties, you're on your own if you decided to follow these instructions), but after some recent upgrades my Debian install (testing/unstable) had awful font rendering on web browsers (everything nice everywhere else somehow). I like to "force" freesans (which is very somooth and anti-aliased) on almost everything on the web, and it was looking like some pixelated Times New Roman or Courier New.
I went googling for solutions...