As Karin M. Cintron, the founder of Karin's ESL PartyLand, says on the start page, this site, which I believe is one of the best of its kind, is a cool way to learn English, with hundreds of useful resources for both students and teachers.
Features:
• A quiz center containing over 75 interactive quizzes on business English, grammar, vocabulary, idioms, slang and phrasal verbs, reading, useful expressions, TOEFL skills and other trivia, all sorted by level of difficulty
• Learning pages for students that cover various topics, each with a discussion guide, many activities, games and quizzes for instant practice, and quality links to more online resources
• Teaching pages for teachers that contain guides, handouts, worksheets and lesson plans for teaching conversation, teaching with film and video, teaching with the Internet, teaching with music, teaching grammar, teaching listening and speaking, teaching reading, writing and vocabulary, and teaching integrated skills
• Discussion forums, e-mail exchange services and links pages for students and teachers
Site URL: http://www.eslpartyland.com/