Cleartype (sub pixel rendering) should only be enabled for LCD... best if it's a DVI LCD, but usable with VGA-connected LCD. The tuning toy
http://www.microsoft.com/typography/...ePowerToy.mspx has options to enable, disable and adjust two parameters.
Expert mode: RGB / BGR stripe pattern = Wizard mode - which looks best (out of two)?
Expert mode: Contrast = Wizard mode (more samples).