When Rihanna sits down tonight with Diane Sawyer on '20/20', it's sure to be one of the biggest interviews of the year. But will it go down as one of the biggest interviews of all time? Over the years, the celebrity interview has become one of the staples of the entertainment industry. Make a huge mistake? Go on the 'Tonight Show' and humbly plead forgiveness. In need of a reputation makeover? Talk to Oprah and shed a tear. Need to generate instant headlines? Letterman is your man. When celebrities open up, crazy things seem to follow, so whatever happens tonight, chances are people will be talking about it tomorrow. In order to help Rihanna prepare, then, we thought we'd give her (and you) a refresher course in some of the most infamous interviews of all time.