Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Img Safe - Host JP1G, GIF and PNG images up to 16MB each.
ImageShack - Unlimited space to host images, easy to use image uploader, albums, photo hosting, sharing, dynamic image resizing on web and mobile.
UltraIMG - UltraIMG is a free image hosting platform.
imgbox - Imgbox is a free image hosting service.
MGER - A free image upload and hosting service.