Ugly fonts in 12.10 even with antialiasing turned on

Make sure you have the ubuntu-desktop package installed. It contains, among other things, the ubuntu-settings package, which includes the default font settings.

If you have it installed and the fonts still look ugly, you can try resetting the configurations of Unity:

• How do I reset GNOME to the defaults?

Here's the default font settings for 12.10:

I assume you are saying ugly to the thin look of the fonts. Though You have anti-aliasing turned on, the hinting is important there. With full hinting, you will get much thinner fonts which do not look great on Unity (It looks good in KDE though).

You should change the hinting to Slight, instead of full. It will give you smoother fonts which is enabled by default in Ubuntu.