I've printed at Target and Wal-Mart.
Target uses kodak paper, wal-mart is fuji. Target was glossy, wal-mart was lustre. I ordered our xmas cards from Costco, and they came out really nice.
This is, of course, uploading and sending the prints online. I had sub-par (by my standards) results from the kodak kiosk at a Target (images were slightly too pink...). I was incredibly pleased, however, with the quality of the Target prints I sent through Yahoo photos. I couldn't even tell they were digital, there was no trace of pixelization.
I like that you can print up to 8x10 online, too. I missed out on the 50 free prints from shutterfly, but I'm planning on trying them out too.