I like the fonts available at Google Fonts but I've noted some sans-serif choices render markedly different when comparing Win XP (IE) to browser on a Mac (Saf, Cr, FF).
An example is Open Sans, which is a very nice (Lucida Grande-like) font on the Mac, but renders pretty bad on Win XP (IE).
Does anyone have experience with using these web fonts and any recommendations which look good regardless of platform?