Dave’s ESL café has some interactive grammar quizzes
Free online English lessons & ESL / EFL resources
Access
to free flash ESL games, free educational ESL and TOEFL
English
Grammar for ESL Students
Daily
Grammar has a very extensive archive of free English Lessons
ESL
Party Land offers you graded exercices and lots of useful links.
This
site offers lots of tests and exercise practice for intermediate and advanced
learners. Specifics include grammar, vocabulary, reading, and business
English. There's also a chat room and a fun game called Trivia Blitz.