One aim of the Jing project is to simplify the process of screen capture and screencasting and it does fulfill this aim. Jing has one of the simplest UI for taking screenshots.
In SnagIt you need to inform the app before hand whether you intend to capture a Window or a region. Jing automatically adjusts the capture boundary when you hover over the edge of the screen.
You can also highlight sections of the captured image, add text, frames and arrows. The Undo/Redo feature is also quite useful.
The captured image can be:
Even capturing video is as simple as capturing an image. Checkout one sample screencast I recorded with Jing
Only complaint from my side is with respect to the stability of the application. Jing keeps crashing now and then and its also a memory hogger.
Which screen capture tool do you use ?