Below is a distillation of "free" university/college level education material.
1) going through up to 200 result links for each of the following queries "free online courses", "open university courses", "free college courses", "free university videos" and "free college videos". [The word "free" is used intentionally in these queries to avoid all the various online universities/colleges/courses that you can pay/apply for]
2) sampling 2-3 courses in each of the sites to evaluate content quality (not delivery, or the expert level of the tutor)
3) weeding out lots of poor material
Very Good quality
MIT Opencourseware - http://ocw.mit.edu/
CMU - http://oli.web.cmu.edu/openlearning/
Health-related Open courses in Johns Hopkins - http://ocw.jhsph.edu/
British Open University - http://openlearn.open.ac.uk/
Stanford's portal in iTunes - http://itunes.stanford.edu/overview.html
(many other universities have such free iTunes stores)
Some of them are at http://continuingstudies.stanford.edu/
Engineering-only is at http://see.stanford.edu/
Berkeley - http://webcast.berkeley.edu/courses.php
UC Irvine - http://ocw.uci.edu/
Utah State Univ - http://ocw.usu.edu/
Yale - http://oyc.yale.edu/
IIT (mainly science and engineering) - http://www.youtube.com/user/nptelhrd
Tufts - http://ocw.tufts.edu/
Notre Dame - http://ocw.nd.edu/
Mainly science - http://www.freesciencelectures.com/ (mix of good and mediocre)
http://www.openculture.com/freeonlinecourses has direct links to specific course pages based on topic.
http://wlh.webhost.utexas.edu/ - Search engine for finding university online courses, but I found that it missed some top links as shown above.
http://www.ocwsearch.com/ - seems slightly better
http://home.comcast.net/~plutarch/lectures.html - pointers to various universities' iTunes and ocw pages
For music, Berklee College of Music offers some free material - http://www.berkleeshares.com/
There were a lot more links but the quality was just so poor that I did not want to quote them here.
For many topics, my favorite is The Teaching Company - http://www.teach12.com/ and its Great Courses series.
For school-level educational material, Khan Academy - http://www.khanacademy.org/ seems very popular.