I have taken several classes from the national teachers at several 4- or 5-day quilt events: John Flynn, Carol Doak, Ellie Sienkewicz, Jeanne Kimball, Mary Sorensen, Eleanor Burns, Ricky Tims, and others.
From local quilt shops, I've taken several - blocks-of-the-month, Yellow Brick Road, Fat Quarter Fun (the pattern, not the book) and others I can't remember but it's been about a dozen.
Our quilt guild has Quilter's Day Camp - please see my separate posting on this for more details (I'm going to type that post right now, so give me half an hour).