What types of posts get traction? In a nutshell, posts that either hit the heart, lead you to "ah-has," consolidate insight, consolidate resources, or help you nail a task. Skellie outlines 7 Types of Blog Posts Which Always Seem to Get Links and Traffic.

Types of Posts
Skellie's list of types of posts:

• Resource lists
• Lists of tips
• Good advice
• Aguing a popular point of view
• Anything with a killer headline
• Q&As with high profile people
• Best of lists

Specialized Versions of Above
I think the following types of posts are variations of above, but worth calling out because of their prevalence on the Web:

• Link lists.  This is a variation of "resource lists", but focused on links.
• Step by steps.  This is a variation of "good advice", but provide prescriptive action.
• Top 10 lists.  This is a variation of "lists of tips" but it's a numbered set. 

Additional Types of Posts
In addition to the types of posts above, I think there's an additional set of patterns:

• Question / Feedback posts.  Posts that ask the community a focused question. 
• Stories with lessons learned.
• Blog carnival.
• Timely hot topic. Timely posts about a relevant topic.