JS-Kit: Comments, reviews, ratings, polls and more…
Abuse Magazine – WordPress plugin: Post Star Rating
Pretty good looking. Add user star ratings to posts, plus list the top X reviewed posts in a sidebar or elsewhere.
WordPress Review Site Plugin – Dan Grossman
Make WordPress go all user-rating-and-reviewy.
E5 Media » Rate Comments Plugin for WordPress
Super basic comment rating plugin from Theron Parlin, who is awesome.
Unobtrusive AJAX Star Rating Bar
Netflix/Amazon style star ratings with no page refreshes.