I’ve activated a plugin that I’ve had on the site for quite a while — WP-PostRatings. With it you can rate each post either on the front page, or on the individual posts. Right now I’m using stars, but the latest version of the plugin comes with quite a few options.

Depending on which option you choose readers can rate posts on a 1-5 scale or on a simple yes or no system. I’m using the star-crystal style. Is there one you like better?