What are your "reference" CDs?

Hi, I would like to know what are your "reference" CD/CD's? My list are Randy Travis, Dixie Chicks, Ronny Cox, Martina McBride, Yanni, Sting, Eagles, Enigma, and Tim Mcgraw. Of course, there are others. As you can see from the list, I listen mostly country and rock. What are some other artist your perfer? BTW,I would use any genre other than the one specifed. Thanks and Happy Listening