Machine Learning has lots of applications. So it just depends on what you call "interesting," which varies person to person so I'll simply list some typical applications.
detecting fraud at banks
identifying which consumers are most likely to respond favorably to direct mail, Groupon deals, Facebook advertisements
trading stocks and derivatives
pricing insurance premiums (Google recently funded a startup that helps natural disaster insurance companies determine prices based on weather patterns due to global warming)
identifying human genes that make people more likely to develop cancer
predicting housing prices for real estate companies
predicting wine-tasting ratings
programmatically reading text from a random photograph
programmatically recognizing faces
autonomous, self-driving cars
If you are a beginner and want to know more about Machine Learning, then check out this course by Intellipaat which will teach you ML from basics: Machine Learning Online Course
And if you are more into videos then do check out this awesome video based on Machine Learning and it's real-life examples:
Check out the following video tutorial by Intellipaat which will teach you ML from basics: