resource recommendations - What are good commercial stock graphic sites for websites/applications?

I am looking for good websites providing royalty free stock images for pay.

I'm not looking for sites that make images available for free and require attribution or non-commercial use; they're already covered in another question.

I'd also like hear some comments of the service:

• What kind of payment options they offer?
  
  
  
  • e.g. do you have to buy a bulk of credits or can items be bought separately? Sometimes buying bulk credits won't suit my projects.
  
  
  
  


• How much do they have content?
  
  
  
  • e.g. psdGraphics is interesting for its payment options, but I found its supply lacking.
  
  
  
  



• How is the overall content quality?
  
  
  
  • e.g. does the site have vast disperse in quality, which usually is the case with big, major sites (such as iStockPhoto or does the site have strict quality requirements?
  
  
  
  

What sites do you use to buy graphics / backgrounds / images for commercial design purposes?

Answer

At GraphicRiver you can buy and sell royalty-free, layered Photoshop files, vectors, icon packs, Adobe add-ons and design templates for just a few dollars. Items are priced on the complexity, quality and use of the file. The site is home to a bustling community of graphic designers and illustrators.

Payment options: Pay-as-you-go, bulk prepaid credits

Price range
Standard licenses: $ 1–25 (+ $2 if not using prepaid credits)
Extended licenses: $ 15-1250 (+ $2 if not using prepaid credits)

Content: ≈ 24k items

Quality: All submissions get screened (with a lot getting rejected), loads of good–quality content not to be found elsewhere (due to royalty rate policy, which favors exclusivity).

Submisser's royalty
Non-exclusive: 25 %

Exclusive: 50–70 %

Notes

You can use paypal or prepaid credits (which you get a small discount on the item for) or just buy individual items. They have a huge library of graphics, buttons, textures, brushes, and other random objects. The quality is quite good. It is all screened and a lot of it gets rejected. They also have very clear licensing agreements and you can pay different prices based on what you want to use it for.