Popular stencils
Simple Rack Elevations
Basic stencil used for documenting rack elevations
AMQP
A simple stencil for drawing AMQP and RabbitMQ topologies.
Windows 8: Dialogs
Dialogs for Windows 8.
A10 Networks
Stencil for A10 Networks Thunder Series Platforms.
BlackBerry User Interface
A very basic stencil for BlackBerry. I've taken care to ensure that the representations of the devices are to scale; everything on the stencil is at 1/2 scale btw if you wanted to design in real size. Please feel free add to this stencil if you think some important controls are missing.
Windows 8: Category views
Category views for Windows 8.
Akka Streams
The Akka project has created the Streams toolkit for creating back-pressured, asynchronous stream processors. Diagramming them out can be quite common, and this stencil is designed to help you do that.
Cross functional diagram
I've used the cross functional diagram and this stencil several time to analyze the organization of different sized enterprises (SMEs and Big enterprises) for my consultancy work. It works well to define the organizational flow and to understand critical points within the organization.
Search (Magnolia CMS)
Search Paragraphs stencil from the Magnolia CMS Standard Templating Kit (STK) Stencil kit.