Stock Photography - Picography
Picography is a site that has many free and paid/premium images available.
Stock Photography - TookaPic
TookaPic has over 67,000 images, and add images to their collection daily.  There is a large set of free images...
Stock Photography - Death To Stock Photos
This is an interesting style of stock photo website.  There are opportunities to download free stock photo packs and there...
Stock Photography - Stocksy
Stocksy is an interesting creative content provider. In addition to having digital images and video, they also have mobile images...
Shutterstock is a well known name in the online stock photography world.  They have a wide variety of different types...
Stock Photography - Pond 5
Pond 5 has stock photography, but also has creative media in a variety of other areas. There is music, video...
Stock Photography - Photodune.net
A stock photo agency that was launched by the Envato digital marketplace.
Photocase is a stock photo agency that aims to provide images that do not look like stocl photos.
Stock Photography, iStockPhotos

iStockPhotos have a collection of royalty free images for you to license for your next project.

Stock Photography - Dreamstime
Dreamstime has over 58 million stock images to choose from, along with a large user community of over 17 million...
Stock Media, 123RF.com
A royalty free stock photo resource that has over 76,783,525 images to choose from.
Stock Photography, DepositPhotos.com

Stock photo agency.

Stock Photography, Bigstock
BigStock or Big Stock Photo agency.
123RF
A stock photo agency that has many different types of content to purchase and use in your website production.
Stock Photo Agency - Bigstock.com

A great stock photo agency by Shutterstock.