An awesome list of high-quality open datasets in public domains (on-going). Most of the data sets listed are free, however, some are not.

I like the vi/vim cheat sheet.

The title link to the ministry of environmental protection of the PRC.

Here is anther aqi site.

BEUTLER INK gathered the biggest stories of the past year in to a picture.

It may be 2012 or 2013, I first found this website.