I thought it might be useful to readers if I brought together all my vocabulary-related “Best…” lists together in one post. Some may need to be updated, but even if you find some dead links, the vast majority should still be active:

The Best Sites Where ELL’s Can Learn Vocabulary

The Best Websites For Developing Academic English Skills & Vocabulary

The Best “I Spy” (Hidden Object) Games For Vocabulary Development

The Best Spelling Sites

Of course, as Robert Pondiscio points out, the best way to develop vocabulary is to read….