I love the Elm Creek series. Those are good books not counting the quilting angle. Earlene Fowler has a series of quilt themed mysteries. I just recently saw Marie Bostwick's book somewhere. I'll have to check her out.
Last visit at Barnes & NOble, I saw what I call 'fluff' mysteries in all kinds of themes - scrapbooking, plumbing, DIY, wine! I guess someone discovered themes work!