Here are, in my opinion, some of the best links for language learning.
German Audio & Video Online: GAVO
Spanish Audio & Video Online: SAVO
Note for Teachers who want to create their own: If you want to create web-based interactive exercises with feedback on your own, my top recommendation is Hot Potatoes, which is free if you use it for academic work and make your exercises accessible to everyone on the web. And that's what the web is all about.
Hot Potatoes Interactive Exerercises with Webbrowser (collection of various grammar topics).
JavaScript Interactive Exerercises with Webbrowser (collection of various grammar topics).
Grammar Handouts, Information, Tables, Flowcharts, etc.
1. Adjective Endings - Flowchart, source URL below. GIF [13 Kb]
http://german.about.com/library/weekly/aa021599.htm (2003)