I have been getting frustrated with the readability of the article body text within Google Reader. It's just a bit too small and I find it much easier to read serif fonts for large sections of text. I also adjusted the line-height to improve legibility.
So I have created a user stylesheet with http://userstyles.org which changes the body text to something a bit better.
Install Stylish extension for Chrome to be able to use this and then head over to http://userstyles.org/styles/58926/google-reader-serif-article-body and you can enable this style on your google reader.