Shutterstock - Shutterstock is a provider of stock photos, illustrations, and vector art. The website allows individuals to purchase a subscription and download copyrighted art for creative projects. Read more about Shutterstock.
Snapwire - Real photos by real people
iStock - Browse the best stock library of royalty free content at prices anyone can afford.
Pixabay - Over 270,000 free photos, vectors and art illustrations
Projectmates - Projectmates by Systemates Inc.
PhotoDune - Royalty-free stock photo marketplace.