The Khan Academy

New and Noteworthy

Physics

Projectile motion, mechanics and electricity and magnetism. Solid understanding of algebra and a basic understanding of trigonometry necessary.

Biology

Covers topics seen in a first year college or high school biology course.

Chemistry

Videos on chemistry (roughly covering a first-year high school or college course).

Organic Chemistry

Topics covered in college organic chemistry course. Basic understanding of basic high school or college chemistry assumed

Cosmology and Astronomy

Videos attempting to grasp a little bit about our Universe (many of the topics associated with "Big History")

Algebra

Topics covered from very basic algebra all the way through algebra II. This is the best algebra playlist to start at if you've never seen algebra before. Once you get your feet wet, you may want to try some of the videos in the "Algebra I Worked Examples" playlist.

Geometry

Videos on geometry. Basic understanding of Algebra I necessary. After this, you'll be ready for Trigonometry.

Precalculus

Non-trigonometry pre-calculus topics. Solid understanding of all of the topics in the "Algebra" playlist should make this playlist pretty digestible.

Trigonometry

Videos on trigonometry. Watch the "Geometry" playlist first if you have trouble understanding the topics covered here.

Probability

Basic probability. Should have a reasonable grounding in basic algebra before watching.

Calculus

Topics covered in the first two or three semesters of college calculus. Everything from limits to derivatives to integrals to vector calculus. Should understand the topics in the pre-calculus playlist first (the limit videos are in both playlists)

Linear Algebra

Matrices, vectors, vector spaces, transformations. Covers all topics in a first year college linear algebra course. This is an advanced course normally taken by science or engineering majors after taking at least two semesters of calculus (although calculus really isn't a prereq) so don't confuse this with regular high school algebra.

Finance

Videos on finance and macroeconomics

Banking and Money

Videos on how banks work and how money is created.

Healthcare and Medicine

Videos about medicine and the healthcare system

History

The history of the world (eventually)!

Khan Academy-Related Talks and Interviews

Collection of interviews with and presentations by Salman Khan. Also a few other mentions of Khan Academy at other talks.