Stevie Wonder is a true legend.
iTunes has a great boxset of his work. Yeah, it's nearly two hundred bucks, but you get almost 600 songs, including all of his classic 70's work. There's also a funky Prince version of Cold Chill.
I got into Stevie Wonder after ganking someone's "At the Close of a Century" box set (back in Rio days). Listening to musicians like him helps one discern between what's hot and what's definitely not.