Far from being a failure of free market capitalism, the Depression was a failure of government. Unfortunately, that failure did not end with the Great Depression. . . . In practice, just as during the Depression, far from promoting stability, the government has itself been the major single source of instability. — Milton Friedman
The book to read on the 2008 financial crisis is, Hidden in Plain Sight: What Really Caused the World’s Worst Financial Crisis and Why It Could Happen Again by Peter Wallison. You can read the introduction before you buy the book here.
This excellent 6-minute video by Nicole Gelinas of the Manhattan Institute nails it. As usual, the popular myths are not even good mythology.