Need fun and engaging photos for your website or blog? Of course you do. Whether it's smiling faces, kids in the snow, yummy food, or serious corporate types, the right pictures can make all the difference in getting prospects to spend more time on your site… and maybe even buy from you!

The good news is that there are plenty of royalty free (unlimited use) stock photo sites to choose from. Many have lots (and lots!) of affordable and free pictures, plus different payment options depending on whether you're looking for just one photo or have ongoing picture needs.

Here's our list of the 28 best free and affordable stock photo sites. We've ranked them based on our editorial review, monthly US visitors (estimated by Compete), and Google page rank (a key factor in determining ranking in search results… the higher the better). And we've used many of them too!

Everyone's needs are different, so definitely take a look at these stock photo websites to see which is best for you. This list doesn't include photo sharing sites like Flickr and Photobucket which can also be good sources (just check licensing before using).

Let us know which stock photo sites you decide to go with… or if you have any favorites you'd like to recommend!