Full Page Screen Capture - I built a Chrome Extension that allows you to save a screenshot of an entire webpage as an image
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Screenshot Designer - Create engaging App Store screenshots
Shutter - Shutter is a feature-rich screenshot program.
Webshot - Free and Open Source screenshot website service
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