Well, chemistry and physics …
Most examples of “The periodic table of …” infographic meme are a little bit silly and somewhat informative. Chris Lake’s The Periodic Table of Content Marketing is plenty silly, but it’s more than somewhat informative.

Major props for leading off with content strategy, though I’d certainly argue in favor of splitting that into multiple strategies – content strategy, of course, but strategies for content marketing, social media, email marketing, and any other tactics you are using.
The Format section is particularly useful. Too many marketers begin and end their content format arsenal with articles. Sure infographics are difficult to do well, but videos and slideshows are much easier to produce beautifully – and effectively. Webinars and events are too often overlooked, as well.
Lake’s Content Types is also really useful – interviews are an easy way to get compelling content without a huge investment of time or creative talent. (Read, budget for creative talent.)
There is the inevitable blurring of lines – is email really a format rather than a platform – but this periodic table is way more useful to most of us than the usual take on that old high school science favorite, even if Formats, Content Types are the only two sets of elements you focus on. (Though you’d be silly not to check out the Metrics section, too.)