Lots of times, albums are uploaded with no scans at all or maybe just really tiny ones. Where do you go usually to get your covers? What sites have the best scans, widest selection, or most complete album art?
For me, my first stop would be www.allcdcovers.com. They have a pretty huge selection of CDs as well as DVDs now. While some of the scans are not really high quality, the sizes generally range around 1200 to 1400 pixels. And they include a lot of the album art like back cover, inlays, and CD itself. Most scans will be downloaded as jpgs.
The downside here is that after about 8 or 10 downloads, you get hit with an anti-robot "please enter the below code to continue" prompt and you end up downloading a huge bmp file instead of a nice jpg. After this download, you're back to pulling down jpgs again for a while. So it's really just a bump in the road if you're going after all the art for somebody's discography, for example. Still worth the trip.
dr.g

Thanks for the tip, I normally just use iTunes to recover artwork then use a script to embed it in to the file (iTunes stores it outside the file). Either that or use google images, but it is pretty hard to find high res 1:1 aspect ratio sometimes, so I'll check out that site :)

I found this site not so long ago, it doesn't always have the newest stuff straight away but i found many covers i needed there.
http://www.freecovers.net/

Freecovers.net Has covers for just about anything dvd,cd,games just about everything
Only 1 thing u need to register, then u can d/l as many covers as u like.
They also have a great forum

This is EXACTLY what I do Fast and easy.

^ same as above ^

Provided the tracks are in the correct order, I let GraceNote add my album art. It's a bastard with some compilations though, as it generally tags the album art for each individual track unless you change the file properties.

Google image search works for me. :)

I use itunes and also Album Art Downloader its not the best but it makes it easier.