Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.

MWSnap - MWSnap is basically a free to use Windows snapping tools that are used for snapping any part of the screen that is currently displaying on the front of all opened programs and windows.

Shutter - Shutter is a feature-rich screenshot program.

FastStone Capture - A powerful, lightweight, yet full-featured screen capture tool that allows you to easily capture...

Snipping Tool - Use Snipping Tool to capture a screen shot, or snip, of any object on your screen, and then annotate, save, or share the image

Snagit - Screen Capture Software for Windows and Mac