When I started this blog over 10 years ago BBC Learning English was easily the best ESL/EFL/ELT site on the web. Since then, of course, many other excellent sites have appeared (and a lot of terrible ones too!), but BBCLE remains a model of the genre. For example, this week the thirtieth and final episode of their Lower Intermediate Course was posted. So you now have a complete state-of-the art, 30-lesson course with video, quizzes, vocabulary and grammar notes — all for free. Let's hope they now follow that up with a more advanced course along the same lines.
When BBCLE revamped their site last year, a lot of the old resources were archived and are not available on the new site. However, you can still access this enormous treasure trove of teaching and learning material here.