Currently, the site uses the Google font Lusitana for most of the content. This has the disadvantage that there is no native italic, resulting in a faux italic which is — bluntly — ugly.
Would it possible to change to a font which has a real italic? Google provide Crimson Text which is similar to Lusitana but has a real italic:
It may be necessary to play a little with the spacing: it certainly looks better slightly more widely spaced than the current setting for Lusitana.
It does appear that Crimson Text behaves better at small sizes on Windows rendering (see the x in text in this comment):
A full-size image of my answer set in Crimson Text is available on imgur — to avoid any artefacts from squishing images inside this column of text. It does appear that Crimson Text renders better on Windows than Lusitana does. If it's thought that Lusitana might be improved upon, it may be worthwhile looking at changing the sans-serif font as well.