I was just recommending to commenter/fellow film geek FourFingerWu a little underrated movie I'd recently come across, Home Before Dark. I'd not heard of it, or the lead actress, Jean Simmons (in the photo), but it turned out to be one the best midcentury American movies I've seen. And Simmons' performance is startlingly beautiful.
SO: What's your favorite underrated thing? Book/movie/TV show/actor/band/album/etc.?