Learning Chocolate (http://www.learningchocolate.com) is a website full of games to learn English, Japanese, Mandarin or Spanish vocabulary in an easy, fun way that really works. The exercises use pictures, sounds and games to make learning a new language as fun as (they report) enjoying a piece of chocolate!
Games typically involve matching and/or spelling. Students can choose from a range of topics, and it suits best basic/intermediate levels. It can be used either in class or as independent study or revision.