How about Susan Boyle?
Susan Boyle's story was perfectly played up by Simon Cowell & Co. and it was a truly epic few minutes of televions when the frumpy middle aged woman from West Lothian (which is a collection of, of of, of, you know....villages!) showed that in her own beautiful she had serious star power and a nice set of pipes.
Unfortunately she also has that middle aged vocal wobble that causes annoying vibrato and let's be honest...she's pretty frumpy.
Still a great triumph for someone who richly deserved it and her debut album made her some serious $$$$.