Good alternatives to Snipping Tool are the following:

• Skitch

Skitch is a screenshot application from Evernote. It is a great tool that allows you to edit and annotate your image. It also has a one-click sharing feature that, with the free Evernote account, allows you to share a file to your Evernote account or to your email.

• Screen Capture

Screen Capture is a free application that allows you to take screenshots and edit them. You can also crop and annotate your file.

• Snagit 

Snagit is a screenshot and video capture application. It is a great tool for capturing screen shots, capturing video, and recording video. This is a great tool for all sorts of needs.