The Guide to Grammar and Writing is an excellent resource for anyone with a grammar/writing question, and the interactive quizzes can be used with students to review content.
Our friends, the Grammar Gorillas, need help identifying parts of speech. If you click on the right word in the sentence, our friends get a banana. And you know, a gorilla with a banana is a gorilla with appeal.
A superb English grammar game where users throw ninja stars at the correct type of word. Download the sentence creator to make your own sentences and play offline. http://ictmagic.wikispaces.com/English