PostImage.org - Provides free image upload and hosting integration for forums.
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Pixeldrain - Fast and easy file sharing, drop a file into the website and get a shareable link right away.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
LightShot - The fastest way to take a customizable screenshot.