I love both Whitesnake and Dio, but the edge goes to Whitesnake. At least with Whitesnake you had one lead singer throughout the years. Unfortunately with Rainbow you had three lead singers, Dio, Bonnett, and Turner. I think that's the main issue for me. I understand that neither band was really stable as far as keeping members, and having a revolving door, but I think it's most important for a band to retain their front man!!!