What's a Wagnerian soprano?
I'm tempted to put forward Waltraud Meier (after all she sang Isolde and Sieglinde and recorded the imolation scene). However, I think that's cheating, she really was a mezzo, despite sometimes singing soprano roles.
I'm guessing that 'Wagnerian soprano' here means the type of dramatic soprano that sang/sings Brunhilde and Isolde. This isn't a voice type that particularly appeals to me and I find Flagstad didn't have the emotional depth that I need in any singing for me to be a fan (despite the glorious scale of her voice and singing). My favourite Brunhilde is Modl, (Which proves that Woodduck is right about some of us being weird), but I consider the greatest Brunhildes to be Leider and Marjorie Lawrence (I know that's herectical, but there goes).
However, that isn't the whole story. I much prefer the lighter types of Wagnerian soprano, such as would be ideal for Elsa, Elizabeth or Sieglinde. I like Grummer and Schwarzkopf in their music. That said, I'm going to go with Cheryl Studer. I was fortunate enough to see one of her Elizabeth's in Vienna and it was one of the most moving performances I have ever seen. She's my favourite Wagnerian soprano.
N.