Weboword is a website dedicated to teaching vocabulary visually.
If students are visual learners this is a great site for learning vocabulary. Not only does the site give a daily word, it also gives a visual, a sentence, a definition and information on the root of the word.
Why I like this: the more exposure students have to vocabulary, the more chances they have to learn new words. Also, by giving a visual picture, students have more ways to learn a word.