Streep gave an incredibly convincing performance in SHE-DEVIL. I just saw it recently, but she looks like she is having so much fun playing this diva that you can't help but love her. I do think the movie belongs to her, although Ed Begley Jr. is quite funny too.
Bobby is 100% right, she is actually hilarious off-screen. Her speeches tend to be a riot... her Emmy speech after winning for ANGELS IN AMERICA is one of my all-time favorite speeches, and of course she always manages to make me laugh in all her interviews, especially when she is making fun of herself.
I don't think this is her best performance by any means, but to say she is not a great comedienne would be ignoring a significant chunk of her long career.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"