OutKast hit their peak

2000's Stankonia had been OutKast's breakout album. But while expectation for the follow-up – Speakerboxxx/The Love Below – was high, few anticipated quite where the duo would go. Originally intended as a solo LP, Andre 3000's half, The Love Below, was a 21st-century take on Prince's funk that spawned the year's biggest anthem, Hey Ya!. Big Boi, meanwhile, stuck to making southern hip-hop, but with flair and a striking honesty. The result was a Grammy for album of the year.