[Copied from email, for the record...]
The default fonts that come with linux don't have proper hints in them, so they're normally quite ugly on screen, no matter which hinter your font renderer uses. Most linux distributions try to compensate by using freetype's autohinter plus antialiasing, but they still don't look very good. (They're either blurry or malformed or both.)
The only way I know to get fonts looking really crisp is to install fonts that have hints in them, use a proper bytecode hinter, and turn off antialiasing.
Here's a breakdown:
default linux fonts + default hinter (autohinter) + antialiasing = mediocre
default linux fonts + default hinter (autohinter) = ugly
default linux fonts + proper bytecode hinter = ugly
good microsoft fonts + default hinter (autohinter)= ugly
good microsoft fonts + proper bytecode hinter = perfect
Right now, the only free high-quality fonts with hints are the Microsoft Core Fonts, and the only linux distribution I know of that has a bytecode hinter built-in is Ubuntu 7.04 (Feisty). So, you have to follow *all* of the instructions in my post. Install Ubuntu Feisty, install the Microsoft fonts, turn off antialiasing/smoothing, and use Microsoft fonts (e.g. Courier New) in your programs. You might have to restart the system before some of those changes take effect.
Good luck!