Elly Sienkiewitz (sp?) Baltimore Album. I have most of her series. Then there's a scattering of everything imaginable!! My bible is Fons and Porter Complete Guide to Quilting (Actually had that spirl bound has highlighting and post-it-notes everywhere) I got it when I first started quilting. Like books on quilting designs, borders, blocks and color!
My newest favorites are: Encyclopedia of Pieced Quilt Patterns and Encyclopedia of Applique both by Barbara Brackman.