What should go in a default git config file?

There is a bewildering array of options that can be set via git config, and that is just the documented ones. Of all of these options, which ones should every developer have set on their box (like user.email)? And what are the most common ones that should be set in common situations (like core.autocrlf=input on Windows)? But please stay away from religious arguments (like the only acceptable setting of core.whitespace being tab-in-indent).