As a product of the 1980s, we imagine you consider yourself an expert of the 1980s. You know all about how Michael Jackson, Madonna and Bruce Springsteen dominated the decade in pop music. But you don't know everything. As we reviewed the pop hits that ruled Billboard's year-end "Hot 100" charts of 1980 to 1989, we were struck as much by who didn't rise to the top as who did: namely, Jackson, Madonna and Springsteen. Not one of those 1980s-leading artists produced a hit that led any single 1980s year. But not to worry. Plenty of other big names came through, including the Wham!- and Faith-era George Michael, the Police-era Sting and the aerobics-era Olivia Newton-John.