I'm in agreement with meat freak about the taste, I've grown many "blue varieties" and don't much care for any of them in the flavor dept. They are lovely to look at, and if you are doing some breeding they would make an interesting parent. Indigo Rose is a very manageable, reliable, productive, pretty variety but also blah in flavor. A wildly productive unstable one that has possibilities is called Dancing with Smurf's from Tom Wagner. If you're into trying some unusual stuff check out Seedsaver's Exchange Yearbook listings, thousands of varieties, crosses, unusual listings. Marianna's tomatoes has great stuff, especially Bill Jeffers creations, Big Cheef is one the most delicious tomatoes I've ever tasted.