Bonnie Hunter's site Quiltville has already been mentioned. She has lots of scrappy patterns and an organizing system:
http://quiltville.com/scrapusersystem.shtml
I also like the Mary's quilt site Lots of patterns:
http://www.maryquilts.com/
I like my scrappy quilts to be somewhat controlled by using a single fabric sashing or patch element thru the whole quilt. I think it unifies the look.