I start thinking, "THIS is my favorite shawl shape!" then see one shaped differently, and have to amend my thinking! I've made triangular, a modified triangular, rectangular, half circle, elongated octagon, crescent, and square. I've yet to try a circular pattern but am keeping my eye out for the perfect design.
I knit with all colors, tonals and even variegated yarns because I give most of my shawls away. That way I always can rationalize casting on another one. I love making them, but there's no way I could wear that many shawls.
My favorite designer is Dee O'Keefe. I have books by Sharon Miller, Elizabeth Lovick, Elizabeth Zimmerman, Nancy Bush, Susanna E. Lewis, Sirri Reimann & Aime Edasi, and Galina Khmeleva & Carol R. Noble. I like playing with the designs... making them mine.
My favorite commercial yarns are those with a wool/silk blend. I love the way my hand spun, sheep to shawl, yarns knit up and block. I like alpaca and llama fleece but prefer that it be blended with wool or maybe silk.