"How To Code HTML, What's New and Obsolete HTML Tags and Attributes
A great quick reference for the transition from HTML 4 to HTML 5. Designed to help authors create polyglot HTML documents, this can also help in creating HTML 4 and XHTML documents, in addition to upgrading to HTML 5. Most HTML cheat sheets, usually based on the technical specifications for a specific version of HTML, show only the valid features in that version of the HTML specs. In contrast, this one helps developers transition from earlier versions of HTML by indicating new features in HTML 5 with a "New" flag and using a strike-through font to indicate the tags and attributes previously used in HTML 4, XHTML 1 and earlier versions that are now obsolete in HTML 5.
For a quick reference of HTML character entities, see the HTML character codes reference.
Required or recommended HTML attributes for the HTML tags are shown in bold.
Something about this format that I really liked. Simple, straight forward, informative and easy to grok...