Hi
I play in 1024x768. Fonts are readable, but in certain windows (help, options, shortcut) verdana is somewhat big. When testing stuff I go in 800x600, where fonts look fine to me. In 640x480 cupandtalon is small and hard to read, but verdana is ok.
I like the user-selectable scaling Pogopuschel explained. It could be extended to cover gui windows too, not everyone wants their windows stretched.